NIFEDIPINE

Posology Adults The recommended starting dose of nifedipine is 5mg every 8 hours swallowed with water with subsequent titration of dosage according to response. The dose may be adjusted to 20mg every 8 hours. Elderly The pharmacokinetics of nifedipine are altered in the elderly so that lower maintenance doses of nifedipine may be required compared to younger patients.

Patients with liver problems Nifedipine is metabolised primarily by the liver and therefore patients with liver dysfunction should be carefully monitored. Patients with renal impairment should not require adjustment of dosage. Paediatric population The safety and efficacy of nifedipine in children under the age 18 years have not been established.

1 Method of administration The capsules should be swallowed whole with a little water.

9%). ADRs derived from post marketing reports, and for which a frequency could not be estimated are printed in bold italic. 1% Frequency Not Known Blood and Lymphatic System Disorders Agranulocytosis Leucopenia Immune System Disorder Allergic reaction Allergic oedema / angioedema (incl.

larynx oedema*) Pruritus Urticaria Rash Anaphylactic/ anaphylactoid reaction Metabolism and Nutrition Disorders Hyperglycaemia Psychiatric Disorders Anxiety reactions Sleep disorders Depression Nervous System Disorders Headache Migraine Vertigo Dizziness Tremor Dysaesthesia, paraesthesia, lethargy Hypoaesthesia, Somnolence Eye disorders Visual disturbances Eye pain Cardiac Disorders Tachycardia Palpitations Chest pain (Angina pectoris) Vascular Disorders Oedema (incl.

6) Calcium channel blockers, such as nifedipine, may contribute to the regulation of mood which in turn may increase the risk of suicide and depressive effects of these drugs. This is possibly because of their lipophilic properties in which they easily penetrate the blood-brain barrier.

They have access to and may interfere with neurones and receptors involved in the regulation of mood. Exacerbation of angina pectoris may occur frequently at the start of treatment with short acting formulations of nifedipine. The occurrence of myocardial infarction has been described although it is not possible to distinguish such an event from the natural course of ischaemic heart disease.

Gingival hyperplasia and, in older men, gynaecomastia have been reported but these are usually reversible on drug withdrawal. Hypersensitivity reactions such as skin rashes and abnormalities of liver function have occurred. These symptoms disappear upon discontinuation of nifedipine.

In dialysis patients with malignant hypertension and hypovolaemia, a distinct fall in blood pressure can occur as a result of vasodilation. Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important.

Nifedipine should be used with caution in patients with hypotension or poor cardiac reserve. In patients with impaired liver function, careful monitoring and, in severe cases, a dose reduction may be necessary. Nifedipine may impair glucose tolerance, necessitating adjustment of antidiabetic treatment in diabetic patients.

Nifedipine may enhance the effects of other antihypertensive agents such as beta- blockers (although this combination is well tolerated) resulting in postural hypotension. Nifedipine will not prevent the occurrence of rebound effects following the discontinuation of other antihypertensive agents.

At doses higher than those recommended, there is some concern about increased mortality and morbidity in the treatment of ischaemic heart disease, in particular after myocardial infarction. In some patients, treatment with short-acting nifedipine induces an exaggerated fall in blood pressure with reflex tachycardia which can cause myocardial ischaemia or other cardiovascular complications.

Nifedipine should be stopped in patients who experience ischaemic pain following its administration. Nifedipine is not a beta-blocker and therefore gives no protection against the dangers of abrupt beta-blocker withdrawal; any such withdrawal should be a gradual reduction of the dose of beta-blocker preferably over 8 - 10 days.

Care must be exercised in patients with very low blood pressure (severe hypotension with systolic pressure less than 90 mm Hg), in cases of manifest heart failure and in the case of severe aortic stenosis. Treatment with short-acting nifedipine can cause cardiovascular complications such as cerebrovascular ischaemia.

As with other vasoactive substances, angina pectoris may very rarely occur (data from spontaneous reports) with immediate release nifedipine, especially at the start of the treatment. Data from clinical studies confirm that the occurrence of angina pectoris attacks is uncommon.

or other dihydropyridines because of the theoretical risk of cross reactivity. - Nifedipine should not be administered to patients with severe aortic stenosis or cardiogenic shock. - Nifedipine should not be used in clinically significant aortic stenosis, unstable angina, or during or within one month of a myocardial infarction.

- Nifedipine should be avoided in patients with a history of acute porphyria. - Nifedipine should not be used for the treatment of acute attacks of angina. The safety of nifedipine in malignant hypertension has not been established. 5).