Amlodipine vs Lisinopril vs Nifedipine

Amlodipine, Lisinopril and Nifedipine compared in detail. Comparison of mode of action, uses, interactions and precautions.

Are you suffering frequently from high blood pressure and it is disrupting your life? Increase in cases of hypertension or high blood pressure is hardly surprising as our modern lifestyle makes us easy prey to this disease.

We consume fatty foods, seldom exercise and have a sedentary mode of life. Hypertension is especially prevalent in people with office jobs or desk jobs. Hectic routine makes us more prone to emotional stress that exacerbates hypertension.

Hypertension also has age and genetic factors. It is crucial to treat this potentially fatal condition because it is indicative of imminent heart disease. Patients with hypertension have anger management issues and are at risk of having a stroke all the time.

Your blood pressure is the product of your heart rate and the resistance your blood vessels offer to the flow of blood. In other words, by increasing or decreasing any one of these factors, you can actually increase or decrease your blood pressure. That’s exactly how much anti-hypertensive drugs work. These drugs either slow down your heart a bit or increase the diameter of your blood vessels so that it can offer lesser resistance to the flow of blood. In some cases, some medicines do both of these functions together.

Treatment of hypertension has many aspects. It includes changes in lifestyle, eating habits, diet and frequent exercise and walks. But antihypertensive drugs are most important in this regard.

Angina is also a prevalent heart condition and many elderly people experience a minor heart episode at some point. Angina makes patient more vulnerable to heart attacks and sudden cardiac death. Men above 45 years and women above 55 years of age are at high risk of angina. Smokers, diabetics, renal disease and obesity also are among risk factors of angina (1).

Anti anginal drugs greatly reduce risk of further cardiac disturbances.

There are many options to choose from and it becomes difficult to decide which medicine will suit you best. In this article we have discussed three popular antianginal and antihypertensive drugs to lend you help in making a decision.

Amlodipine

Are you enjoying a casual game of chess at the club with your friends, tucking into a steak and suddenly you experience pain in your chest? This chest pain that gradually intensifies is called as angina and indicates underlying heart dysfunction and disease. Therefore, its treatment should not be taken lightly. Besides regular exercise and diet control your doctor will prescribe you medications to keep your blood pressure level normal at all times. That is where amlodipine comes in. Amlodipine belongs to a group of drugs called calcium blockers. It widens blood vessels and increases blood flow.

It is on World Health Organization’s List Of Essential Medicines and considered among important medications in a basic health system (2).

Calcium channel blockers

Calcium channel blockers are a class of drugs that inhibit movement of calcium ions through cells of body. They are also known as calcium channel antagonists. They are used to treat a wide range of cardiac diseases especially hypertension.

They are further classified as (2):

Dihydropyridine

These calcium channel blockers are derived from molecule dihydropyridine and are useful in reducing systemic vascular resistance and arterial pressure. Sometimes when they are used to treat angina, resulting vasodilaton and hypotension can cause reflex tachycardia. This can be detrimental for patients with ischemic symptoms because of increase in oxygen  demand of heart tissues. Members of this class are designated suffix “-dipine”. Amlodipine, the drug under discussion is also member of this sub group.

Non-hydropyridine

• Phenylalkylamine
• Benzothiazepine
• Non selective

Mode of action of calcium channel blockers

In tissues of our body, the concentration of calcium ions outside of cells is normally about ten thousand-fold higher than the concentration within the cells. Calcium channels are embedded into membranes of some cells. When these cells receive a particular signal, the gates of channels open, letting calcium rush into the cell. The resulting increase in calcium in body cells has different effects in various types of cells. Calcium channel antagonists prevent or reduce the opening of these channels and thereby reduce these effects.

Voltage-dependent calcium channels are responsible for excitation-contraction coupling of skeletal, smooth, and cardiac muscle and for regulation of aldosterone and cortisol secretion in endocrine cells of the adrenal cortex. In heart, they are also involved in the propagation of pacemaker signals. (2)

Calcium channel blockers used as medicines for treatment of cardiac conditions primarily have four effects:

• They act on vascular smooth muscle and reduce contraction of arteries and bring about an increase in arterial diameter. Thus, they cause vasodilation. They do not exert their effect on venous smooth muscle.
• They act on muscles of heart or myocardium and reduce force of contraction of heart.
• They slow down heart beat by slowing down conduction of electrical activity within the heart.
• They lower blood pressure by inhibiting calcium signal on adrenal cortex cells. This reduces aldosterone production directly and alleviates blood pressure.

The calcium channel blocker under discussion is amlodipine. Features, actions and uses of amlodipine are described as under:

Mechanism of action

Contraction of cardiac muscle and vascular smooth muscles depends upon movement of extracellular calcium ions into these cells through designated ion channels. Amlodipine inhibits movement of calcium ions into these muscle cells (3). Its effect is more pronounced on vascular smooth muscle cells. It is a peripheral arterial vasodilator and acts directly on vascular smooth muscle tissue to bring about reduction in blood pressure.

Amlodipine dilates arteries and elevates the flow of blood to the heart and is effective in preventing heart pain (angina) resulting from reduced flow of blood to the heart caused by coronary artery spasm (contraction). Relaxation of muscles lining the arteries in the rest of the body alleviates blood pressure, which reduces work load that the heart must do to pump blood to the body. Decreasing  work of the heart also lessens the heart muscle's requirement for oxygen, and thereby further helps to prevent angina in patients with coronary artery disease.

Mechanisms by which this drug relieves angina are:

• In treatment of stable angina, amlodipine decreases the total peripheral resistance or after load against which the heart works and lowers the rate pressure product, thereby lowering myocardial oxygen demand.
• In treatment of prinzmetal’s angina, amlodipine blocks spasm of the coronary arteries and is useful in restoration of  blood flow in coronary arteries and arterioles.

Medical uses

Amlodipine is used to treat patients suffering from following medical conditions:

• High blood pressure or hypertension
• Angina. It is chest pain caused when heart muscles do not receive adequate supply of oxygen rich blood. Angina feels like pressure or squeezing in chest of patient. Pain can also occur in shoulders, arms, jaw or back. Angina is an indicator of coronary heart disease.
• Coronary artery disease. It is also known as ischemic heart disease and includes heart problems such as stable angina, myocardial infarction and sudden coronary death. A common sign is chest pain or discomfort, stabbing pains in left arm that may travel into shoulder, back and neck. Risk factors include (4):
  • High blood pressure or hypertension
  • Emotional distress
  • Smoking
  • Diabetes
  • Obesity
  • Lack of exercise
  • High blood cholesterol
  • Excessive alcohol intake

Side effects

Like every drug, amlodipine has its uses as well as side effects. Side effects experienced while using this drug are (5):

General

Amlodipine is usually a well-tolerated drug. Headache and edema are most widely observed adverse effects.

Gastrointestinal

Adverse effects on GIT include:

• Nausea
• Dysphagia or difficulty in swallowing
• Anorexia
• Constipation
• Dry mouth
• Flatulence
• Vomiting

Hepatic

This drug can cause liver damage and side effects include jaundice and elevation of hepatic enzymes.  Sometimes, these cases were severe enough to warrant hospitalization.

Hematological

Hematological adverse effects include:

• Severe thrombocytopenia especially in patients of renal disease
• Leucopenia
• Purpura

Renal

Renal side effects occur rarely but are not unheard of. Glomerular nephritis has been reported in some cases.

Cardiovascular

Cardiovascular adverse effects include:

• Palipitation
• Arrhytmia
• Ventricular tachycardia. It means abnormal or very rapid heartbeat caused by malfunctioning of one of heart’s ventricles. Patients of ventricular tachycardia have pulse of more than 100 beats per minute.
• Atrial fibrillation. It is an abnormal heart rhythm. There is rapid and irregular beating. It often begins as brief periods of abnormal rapid beating that become longer and more constant over time.
• Bradycardia
• Chest pain
• Hypotension or low blood pressure
• In patients suffering from severe coronary artery disease, amlodipine can increase the frequency and severity of angina and chest pain or actually trigger a heart attack on rare occasions. This phenomenon usually occurs when patient first starts using amlodipine, or at the time of an increase in dosage. Excessive lowering of blood pressure or hypotension during start of amlodipine treatment can occur, especially in those patients already taking other medications that lower blood pressure. In rare instances, congestive heart failure has been linked with amlodipine use, mostly in patients already taking a beta blocker.

Nervous system

Side effects on nervous system include headache, dizziness and somnolence.

Metabolic

Metabolic side effects are:

• Hyperglycemia
• Thirst
• Weight fall
• Acute porphyria

Psychiatric

Psychiatric adverse effects include:

• Male sexual dysfunction
• Abnormal dreams
• Anxiety
• Depression
• Insomnia

Dermatological

Dermatological adverse effects are:

• Rash
• Increased sweating
• Pruritus

Routes of administration

This drug is available for oral administration in form of tablets of 2.5, 5 and 10 mg tablets.

Dosage

The recommended initiation dosage of amlodipine for children and adults is 2.5- 5 mg daily once a day. Maximum dose for adults is 10 mg and maximum dose for children is 5 mg daily. Amlodipine is inactivated largely bby liver and in patients with liver dysfunction, dose has to be brought down so it is well tolerated by patient (6).

Drug interactions

Using amlodipine alongside sildenafil (drug present in Viagra) and similar drugs used for treating erectile dysfunction may trigger excessive lowering of  blood pressure with complications, particularly fainting upon standing (orthostatic hypotension).

Amlodipine greatly increases blood levels of simvastatin (Zocor). Dose of simvastatin should be limited to 20 mg daily in patients using amlodipine.

Ketoconazole (Nizoral, Extina, Xolegel, Kuric), itraconazole (Sporanox), ritonavir (Norvir) and drugs that are potent inhibitors of amlodipine inactivation in liver elevate levels of amlodipine in blood, resulting in excessive blood pressure reduction (7).

Contraindications

Use of amlodipine should be avoided in following scenarios (8):

Nursing females

Amlodipine is contraindicated in mothers who breastfeed because of possible toxic effects on infant.

Pregnancy

Amlodipine has been assigned to pregnancy category C by experts. Medical studies in animals have revealed decreased litter size and intrauterine deaths, as well as prolonged gestation after oral doses exceeding 8 to 23 times the maximum recommended human dose. Amlodipine should only be given during pregnancy when benefits outweigh risk to mother and fetus.

Cardiogenic shock

Cardiogenic shock is a potentially fatal medical condition which is caused by insufficient circulation of blood due to failure of ventricles of heart to function properly.   Taking amlodipine in this condition can worsen health.

Unstable angina

Aortic stenosis

It is narrowing of exit of left ventricle of heart leading to complications and disturbance in functions of heart. It gradually gets worse over time.

Precautions

Before taking this medicine inform your doctor if you are suffering from congestive heart failure or liver disease.

Drinking alcohol can further aggravate hypotension and may increase certain adverse effects of amlodipine.

Your chest pain may increase when you initially begin to take this medication. If it persists and becomes worse, inform your doctor.

For heart patients, amlodipine is part of a complete treatment that includes exercise, diet and weight control. Follow other aspects of this treatment closely along with amlodipine.

How to take amlodipine

Take amlodipine exactly as prescribed by your cardiologist or doctor. Do not increase or decrease dosage on your own behest. Follow the directions of prescription label.  Amlodipine can be taken on an empty or full stomach and before or after meals. After taking this medicine, avoid getting up too fast from a horizontal position as you may feel dizzy and experience a head rush. This is due to lowered blood pressure. Get up slowly and steadily to avoid dizziness. In case you skip a dose, do not take two doses together (9).

Lisinopril

Lisinopril is a drug belonging to ACE inhibitor class. It is used in treatment of cardiac patients and is effective in treating hypertension, congestive heart failure and improving health after an episode of cardiac arrest (10).

ACE inhibitors

Angiotensin converting enzyme inhibitors are a class of drugs used for treatment of elevated blood pressure or hypertension and congestive heart failure.  This class of drugs relaxes blood vessels; bring about decrease in blood volume and oxygen demand of heart.

Classification

ACE inhibitors are identified by presence of suffix “-pril” in their names. They can be divided into three groups (11):

• Sulfhydryl containing agents
• Dicarboxylate containing agents
• Phosphonate containing agents

Mode of action

ACE inhibitors treat hypertension by decreasing activity of renin angiotensin aldosterone system. This system carries out main causal events in development of hypertension in people with diabetes mellitus (12).

Renin angiotensin aldosterone system

One of our body’s mechanism for maintaining blood pressure is release of a protein called renin from cells in kidney (from the juxtaglomerular apparatus). This yields another protein, angiotensin.

This system is activated in response to decrease in blood pressure (hypotension) and is associated to disturbances in salt-water balance of body, such as low sodium concentration in the distal tubules of the kidney, decreased blood volume, stimulation of kidney by sympathetic nervous system.

In such a scenario, the kidneys release renin, which acts as an enzyme and cuts off all but the first 10 amino acid residues of angiotensinogen (a protein produced in the liver which circulates in the blood).

These 10 residues are collectively known as angiotensin I. ACE then removes  further two residues, converting angiotensin I into angiotensin II. Angiotensin II is found in the vessels around lungs and in the endothelium of many blood vessels.

The system elevates blood pressure by increasing  amount of salt and water the body retains, plus angiotensin is also very good at causing the blood vessels to tighten (an effective vasoconstrictor).

ACE inhibitors exert their action by blocking conversion of angiotension I to angiotensin II. They increase capacity of veins, decrease cardiac output, lower arteriolar resistance and lead to increased secretion of sodium in urine.

A widely used ACE inhibitor, lisinopril is explained below:

Medical uses of Lisinopril

Lisinopril is used to treat the following medical conditions:

• It is used to treat hypertension or high blood pressure. Treating hypertensions reduces risk of strokes, heart attacks and renal problems.
• To treat heart failure and cardiac arrest.
• To improve condition of patient post episode of cardiac arrest.
• To prevent renal and retinal complications of diabetes.

Mechanism of action

Like all ACE inhibitors, lisinopril acts by blocking activity of angiotensin converting enzyme. Inhibition of activity of this enzyme results in decreased plasma angiotensin II which leads to decreased vasopressor activity and to decreased aldosterone secretion. It is a potent antihypertensive.

Adverse effects

General

General adverse effects of lisinopril are:

• Cough
• Vertigo and dizziness
• Fatigue
• Nausea
• Diarrhea
• Sneezing
• Runny nose
• Rash
• Angioedema
• Itching

Gastrointestinal

• Vomiting
• Dry mouth
• Nausea
• Pancreatitis
• Flatulence
• Taste disturbance
• Bloating
• Abdominal pain

Cardiovascular

Hypotension

Hypotension in patients with sodium deficiency is frequent. Patients report pounding heart and chest pain. Lisinopril can cause symptomatic hypotension, sometimes complicated by oliguria, progressive azotemia, acute renal failure or death. Patients at higher risk of dangerous hypotension include those with the following conditions : heart failure with systolic blood pressure below 100 mmHg, ischemic heart disease, cerebrovascular disease, hyponatremia, high dose diuretic therapy, renal dialysis, or severe volume and salt depletion.

In these patients, Lisinopril should be started under very close medical supervision and such patients should be observed closely for the first two weeks of treatment and whenever the dose of lisinopril is increased. Avoid use of lisinopril in patients who are hemodynamically unstable after acute myocardial infarction.

Hypotension is also possible in patients with severe aortic stenosis or hypertrophic cardiomyopathy during lisinopril therapy.

Palpitations are common

Angioneurotic edema

Raynaud’s phenomenon

It is excessively reduced blood flow causing discoloration of finger and toes. It is caused by vasospasm that decrease blood supply to target organs.

Renal

Renal adverse effects are very common and include raised levels of creatinine, renal insufficiency, dark urine (melanuria) and decreased urination (oliguria).

Hepatic

Side effects on liver include disturbance in levels of hepatic enzymes, yellowing of eyes or skin indicating jaundice and cholestatic jaundice.

Respiratory

In some patients, especially black patients, lisinopril treatment is discontinued due to high incidence of cough. Bronchospasm has also been reported in some patients.

Metabolic

Metabolic disturbances reported in patients on lisinopril therapy are:

• Hyperkalemia
• Gout

Dermatological

Adverse effects on skin include:

• Pruritis
• Rash and itching
• Sweating
• Skin lesions
• Steven-Johnson syndrome. It is a type of epidermal necrolysis in which cell death causes epidermis to separate from dermis. It is a hypersensitivity complex.

Psychiatric

Psychiatric side effects caused by lisinopril therapy are:

• Memory impairment
• Confusion
• Somnolence
• Irritability

Nervous system

Headache, syncope and dizziness are common side effects among patients using lisinopril.

Brand name

Lisinopril is available in market by the trade name Zestril.

Administration

Lisinopril is available for oral use in form of tablets.

Contraindications

Pregnancy

Lisinopril causes high fetal toxicity and pregnant mothers are strongly advised to not use it. Ingestion of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal kidney function, development and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be linked with fetal pulmonary hypoplasia and skeletal deformations.

Possible neonatal toxic effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue lisinopril as soon as possible. It has been assigned category C during first trimester and category D during second and third trimesters. If you become pregnant during lisinopril treatment, immediately discontinue its use (13).

Nursing mothers

Harmful effects to mother or baby when nursing mother is using lisinopril have not been established yet but still this drug should only be prescribed to nursing mothers when absolutely vital.

Race

Adverse effects of lisinopril such as hypotension and cough are more common among black people.

Angioedema

Lisinopril aggravates angioedema and therefore patients with history of angioedema are not prescribed this drug.

Hypersensitivity

Do not use this drug if you are allergic to lisinopril or any component of Zestril.

Aliskiren containing drugs

Combination of aliskiren containing drugs and lisinopril is contraindicated in diabetic patients. It should be avoided in people with creatinine clearance less than 60ml/min. This combination increases hyperkalemic, hypotensive and nephrotoxic adverse effects of lisinopril. Patients using this combination should be monitored carefully.

Hyperkalemia

Serum potassium should be recorded periodically in patients receiving lisinopril. Drugs that inhibit the renin angiotensin system and ACE enzyme activity can cause hyperkalemia. Risk factors for incidence of hyperkalemia are renal insufficiency, diabetes mellitus, and the concomitant use of potassium-sparing diuretics, potassium supplements and potassium-containing salt substitutes.

Impaired renal function

Observe renal function periodically in patients treated with lisinopril. Changes in renal function including acute renal failure can be caused by drugs that block activity of renin-angiotensin system.

Patients whose renal function depends partially on the activity of the renin-angiotensin system (eg, patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, post-myocardial infarction or volume depletion) may be at higher risk of developing acute renal failure.

Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function while using lisinopril.

Use of diuretics

Patients using diuretics are more vulnerable to developing hypotension after initiating lisinopril therapy. These effects can be minimized by adjusting dose of medication.

Use of Non-Steroidal Inflammatory Drugs NSAIDs

In elderly patients especially those on diuretic therapy or with impaired renal function, administration of NSAIDS including cyclooxygenase enzyme inhibitors along with lisinopril may cause renal damage leading to acute renal failure.

Precautions

Exercise following precautions prior to initiating lisinopril therapy (14):

• Inform your doctor about your complete medical history especially if you experienced any renal disturbances or are on dialysis. Also tell him if you have liver disease, diabetes or high levels of potassium in your blood.
• Inform your doctor about other drugs that you are taking to avoid lisinopril drug interactions.
• Alcohol can lower blood pressure so patients on lisinopril are advised to not consume alcohol as it can aggravate hypotension.
• Immediately inform your doctor if you find out that you are pregnant during period of lisinopril therapy. Use effective birth control while on lisinopril medication.

Dosage

Lisinopril is available by trade name Zestril in tablet form for oral use (15). It is available in various strengths, ranging from 2.5 mg to 40 mg.

Typically, lisinopril is taken once a day. The time around which lisinopril is taken must be same every day.

Your cardiologist or doctor will prescribe a low dose at first and gradually increase the dose. For hypertensive patients, doage of 20-40mg per day is recommended.

When treating patients of cardiac failure, dose of drug prescribed ranges from 5-40 mg a day.

For children, 5 mg dose is given.

Over dosage

Symptoms of lisinopril overdosage are:

• Dizziness
• Lightheadedness
• Fainting

Immediately contact doctor in case of over dosage. If condition is serious, rush the patient to hospital or call emergency services.

How to take Lisinopril?

Take lisinopril exactly as prescribed by your doctor. Follow all directions on label of medicine. Do not take this medication in larger or smaller doses than prescribed or for longer period of time. It can be taken with or without food, before or after meals. Drink plenty of water during time that you use this medicine as you can easily become dehydrated while using it.

Check your blood pressure often to determine if you are suffering from severe hypotension and get medical tests done periodically especially liver and renal function tests.

If you need a surgical procedure done, inform your surgeon and ask if you need to discontinue your medication as anesthetics are also hypotensive.

You store the medicine at room temperature. Keep it away from moisture and heat.

Nifedipine

Nifedipine belongs to calcium channel blocker group of drugs (16).  It is primarily a relaxant of cardiac muscles and blood vessels. It is a yellow crystalline substance, insoluble in water but soluble in ethanol. Nifedipine is enlisted among World Health Organization’s list of essential medicines in a basic healthcare system. It is an effective antihypertensive and anti anginal drug.

Mechanism of action

The mechanism by which nifedipine reduces arterial blood pressure includes peripheral arterial vasodilatation and, as a result, a lowering of peripheral vascular resistance (17). The elevated peripheral vascular resistance, an important underlying cause of hypertension, results from an increase in active tension in vascular smooth muscle. Studies have shown that increase in active tension reflects an increase in cytosolic free calcium.

Nifedipine is a peripheral arterial vasodilator which exerts its effect directly on vascular smooth muscle. The binding of nifedipine to voltage-dependent and receptor-operated channels in vascular smooth muscle results in blockade of calcium influx through these channels.

Stores of intracellular calcium in vascular smooth muscle are reduced and thus dependent upon the influx of extracellular calcium for muscular contraction to occur. The reduction in calcium influx by nifedipine causes vasodilation in arteries and decreased peripheral vascular resistance which results in reduced hypertension.

Nifedipine blocks L-type calcium channels which are high voltage activated family of voltage dependent calcium channels. “L” stands for long lasting and means that calcium channel is activated for long time. By blocking them, nifedipine has a very potent anti-hypertensive effect.

Medical uses

Medical uses of nifedipine are as follows (18):

• It is a potent anti anginal especially effective in treating Prinzmetal’s angina. During Prinzmetal’s angina, pain is felt in chest in a state of rest and occurs in cycles. It is caused by narrowing of coronary arteries caused by contraction of smooth muscles within vessel walls.
• To treat hypertension.
• It is used to delay premature labor in pregnant women.
• It is used to treat high altitude pulmonary edema.
• Useful in treating Raynaud’s phenomenon in which there is insufficient blood flow to parts of body.

Side effects

General

Common side effects of nifedine therapy are (19):

• Mild dizziness
• Weakness
• Headache
• Flushing, tingly feeling
• Tremors
• Muscle cramps
• Cough
• Wheezing, sore throat

Gastrointestinal

Gastrointestinal adverse effects among patients using nifedipine are common and include:

• Nausea
• Heartburn
• Constipation
• Abdominal pain
• Dry mouth
• Dyspepsia
• Flatulence
• Gastrointestinal obstruction due to bezoar formation

Hepatic

Nifedipine is not highly hepatotoxic but rare cases of hepatitis have been reported. Nifedipine linked hepatitis is dose dependent and mostly result of hypersensitivity to drug. In patients with liver disease, nifedipine may increase hepatic portal venous hypertension.

Renal

Renal side effects include formation of renal calculi. Elderly patients suffering from renal disease or arteriosclerotic disease are at high risk of renal insufficiency.

Cardiovascular

Cardiovascular side effects include:

• Peripheral edema
• Hypotension
• Palpitations
• Myocardial infarction
• Congestive heart failure
• Nifedipine associated hypotension may cause retinal, coronary or cerebral ischemia resulting in visual field defects, angina or a stroke.

Hematological

Hematological side effects include:

• Purpura
• Eosinophilia
• Lymphadenopathy

Dermatological

Dermatological adverse effects induced by nifedipine are:

• Pruritus
• Dematitis
• Uritacaria

Respiratory

Patients using nifedipine sometimes develop pulmonary edema. Dyspnea, cough, nasal congestion, wheezing and sore throat are also experienced.

Musculoskeletal

Musculoskeletal side effects include muscle cramps and joint stiffness.

Precautions

Nifedipine should be used with care in following situations (20):

Excessive hypotension

Although, in most patients, the blood pressure lowering effect of nifedipine is modest and well tolerated, sometimes patients have had excessive and poorly tolerated hypotension. These responses have usually occurred during beginning of treatment or at the time of subsequent upward dosage adjustment. Although patients have rarely experienced excessive hypotension on nifedipine alone, this may be more common in patients on beta blocker medication. Although not approved for this purpose by medical experts, nifedipine has been used (orally and sublingually) for acute reduction of blood pressure. Several reports describe cases of excessive hypotension, stroke and myocardial infarction, and death when immediate-release nifedipine was used in this way. Nifedipine should not be used for the acute reduction of blood pressure as the after effects could be potentially fatal.

During surgery

Severe hypotension and increased fluid volume requirements have been reported in patients receiving nifedipine together with a beta-blocking agent who underwent coronary artery surgery using high dose fentanyl anesthesia. The interaction with high dose fentanyl appears to be caused by combination of nifedipine and a beta blocker, but the possibility that it may occur with nifedipine alone, with low doses of fentanyl, in other surgical procedures, or with other narcotic analgesics cannot be excluded from consideration. In nifedipine treated patients where surgery using high dose fentanyl anesthesia is about to take place, physician should be aware of these potential problems and, if the patient's condition permits, sufficient time (at least 36 hours) should be allowed for nifedipine to be expelled out of patient’s system prior to surgery.

After myocardial infarction or coronary artery disease

Sometimes, patients, especially those who have severe obstructive coronary artery disease, have developed increased frequency, duration, severity of angina or myocardial infarction on starting nifedipine or at the time of dosage increase. The mechanism of this effect has not been determined.

Nifedipine should not be given to cardiac patients in the first week or two after     myocardial infarction, and they should also be avoided in the setting of acute coronary syndrome (when infarction may be possible).

Beta blocker withdrawal

Patients recently taken off from beta blocker therapy may develop a withdrawal syndrome with increased angina, probably related to increased sensitivity to catecholamines. Starting nifedipine treatment will not prevent this occurrence and might be expected to aggravate it by provoking reflex catecholamine release. It is important to counter withdrawal effects of beta blockers if possible, rather than stopping them abruptly before beginning nifedipine therapy.

Pregnancy and breast feeding

Toxic effects of using nifedipine in pregnant women have not been determined yet. Inform your doctor if you become pregnant. Nifedipine use should be avoided by nursing mothers because it can pass into milk and cause harm to the baby.

Driving

Consumption of this drug may cause dizziness so do not drive or operate heavy machinery after taking it.

Use of multivitamins

Use of multivitamins can decrease therapeutic ability of this drug. You may need a dose adjustment.

Grapefruit juice

Grapefruit juice exacerbates side effects of nifedipine such as headache; low blood pressure and irregular heartbeat therefore avoid drinking this juice if you are taking nifedipine.

Lactose intolerance

Nifedipin extended release tablets usually contain lactose. Inform your doctor if you lactose intolerance.

Routes of administration

Nifedipine is available for oral or sublingual administration. Sublingual form has more side effects.

Trade names

Nifedipine is available by trade names Procardia, Adalat and Nifediac.

How to take this medicine

Before you begin to use this drug, inform your doctor if you have:

• Severe chronic obstructive pulmonary disease
• Renal disease
• Congestive heart failure
• If you are taking other medications
• If you are pregnant.

Only take dosage strictly as prescribed by your doctor. Read instructions carefully on medicine label and follow them.

Extended release tablets of nifedipine are taken on an empty stomach and should be ingested prior to meals. Do not crush or chew the tablet and swallow it whole.

Some preparations of nifedipine have a coating that is passed in stool. Do not be alarmed as it is not harmful and will not alter effectiveness of drug.

Do not stop nifedipine therapy at once. This has proved to be very harmful.

You should store the medicine at room temperature. Also keep it away from sunlight and moisture. Keep out of reach of children as they may accidentally ingest it.

Amlodipine vs Lisinopril vs Nifedipine compared

Now that you have complete information regarding these drugs, it is easy to compare them and determine which one will suit your medical requirements.

Classification

Each group or class of drugs has particular attributes.

• Amlodipine belongs to calcium channel blocker class of drugs.
• Lisinopril is an angiotensin converting enzyme inhibitor.
• Nifedipine is also a calcium channel blocker.

Mechanism of action

As far as mechanisms of action are concerned, the difference between those three drugs is as follows:

• Amlodipine blocks movement of calcium ions into cardiac muscle cells especially on vascular smooth muscle cells.
• Lisinopril inhibits ACE activity and decreases levels of angiotensin II in plasma.
• Nifedipine blocks L type calcium channels, acting as an antihypertensive.

Medical uses

Here is a brief comparison of medical uses of Amlodipine vs Lisinopril vs Nifedipine:

• Amlodipine is used to treat angina, high blood pressure and coronary artery disease. It does not have any additional medical benefits like nifedipine.
• Lisinopril is used to treat hypertension, to prevent cardiac arrest and for improvement of condition of patient after heart attack.
• Nifedipine is primarily used to treat angina, hypertension and to delay early labor. Unlike amlodipine, nifedipine cannot be used to treat coronary artery disease but in fact is harmful in this medical condition. Unlike lisinopril, nifedipine use should be sternly avoided immediately after cardiac arrest or heart attack.

Side effects

Some of the side effects are common but others are specific to each drug. Here is a brief comparison of side effects of Amlodipine vs Lisinopril vs Nifedipine:

• Amlodipine is a well tolerated drug. Side effects mainly include headache and edema.
• Side effects of lisinopril include hypotension (especially in patients with salt disturbances), respiratory disturbances, renal function impairment and angioedema. Side effects are more common in black people. The other two drugs do not have this characteristic.
• Side effects of nifedipine include hypotension, nifedipine associated hepatitis, wheezing, cough, etc.

Use in pregnancy

Here is a brief comparision of Amlodipine vs Lisinopril vs Nifedipine with respect to their use in pregnacy:

• Use of amlodipine has toxic effects on fetus during pregnancy.
• Lisinopril is highly fetotoxic especially in second and third trimesters.
• Nifedipine has not been proven to be harmful during pregnancy. But nursing mothers should avoid its use.

Contraindications

A brief comparision of contraindications of Amlodipine vs Lisinopril vs Nifedipine can be found below:

• Amlodipine should not be used in case of cardiogenic shock or unstable angina.
• Lisinopril is contraindicated in patients with diabetes and renal disease undergoing dialysis and using diuretics.
• Nifedipine use should be avoided for two, three weeks after a heart attack and in case of severe coronary disease.

Use before surgery

A brief comparision of Amlodipine vs Lisinopril vs Nifedipine with respect to their use before surgery:

• Amlodipine can be used prior to a surgical procedure.
• Lisinopril should not be used before a surgical procedure.
• Nifedipine should not be used before surgery.

Conclusion

This post featured a detailed comparison of Amlodipine vs Lisinopril vs Nifedipine. In addition to detailed description of classification, medical use, side effects and precautions of each individual drug, a summary comparison of the three drugs is provided at the end of the post. While we strive to provide the readers with the most accurate information on Amlodipine, Lisinopril and Nifedipine you should never rely on any information found on the web. Always ask your physician for proper treatment if you have any medical issues or do not feel well. The information in this article should only be used as a complementary information on each drug and does not replace a proper medical consultation!