FENAMON SR Modified release tablet Ref.[28313] Active ingredients: Nifedipine

Posology

The recommended starting dose of nifedipine is 10 mg every 12 hours swallowed with water with subsequent titration of dosage according to response. The dose may be adjusted to 40 mg every 12 hours, to a maximum daily dose of 80 mg.

Co-administration with CYP 3A4 inhibitors or CYP 3A4 inducers may result in the recommendation to adapt the nifedipine dose or not to use nifedipine at all (see section 4.5).

Duration of treatment

Treatment may be continued indefinitely.

Additional information on special populations

Paediatric population

Children and adolescents:

The safety and efficacy of nifedipine in children below 18 years of age has not been established. Currently available data for the use of nifedipine in hypertension are described in section 5.1

Elderly (>65 years)

The pharmacokinetics of nifedipine are altered in the elderly so that lower maintenance doses of nifedipine may be required

Patients with hepatic impairment

Nifedipine is metabolised primarily by the liver and therefore patients with liver dysfunction should be carefully monitored and in severe cases, a dose reduction may be necessary.

Patients with renal impairment

Based on pharmacokinetic data, no dosage adjustment is required in patients with renal impairment (see section 5.2).

Method of administration

Oral use.

As a rule, tablets are swallowed whole with a little liquid, either with or without food.

Nifedipine should not be taken with grapefruit juice (see section 4.5).

Symptoms

The following symptoms are observed in cases of severe nifedipine intoxication:

Disturbances of consciousness to the point of coma, a drop in blood pressure, tachycardia, bradycardia, hyperglycaemia, metabolic acidosis, hypoxia, cardiogenic shock with pulmonary oedema.

Management

As far as treatment is concerned, elimination of nifedipine and the restoration of stable cardiovascular conditions have priority. After oral ingestion thorough gastric lavage is indicated, if necessary in combination with irrigation of the small intestine.

Elimination must be as complete as possible, including the small intestine, to prevent the otherwise inevitable subsequent absorption of the active substance.

The benefit of gastric decontamination is uncertain.

1. Consider activated charcoal (50 g for adults, 1 g/kg for children) if the patient presents within 1 hour of ingestion of a potentially toxic amount. Although it may seem reasonable to assume that late administration of activated charcoal may be beneficial for sustained release (SR, MR) preparations there is no evidence to support this.
2. Alternatively consider gastric lavage in adults within 1 hour of a potentially life-threatening overdose.
3. Consider further doses of activated charcoal every 4 hours if a clinically significant amount of a sustained release preparation has been ingested with a single dose of an osmotic laxative (e.g. sorbitol, lactulose or magnesium sulfate).
4. Asymptomatic patients should be observed for at least 4 hours after ingestion and for 12 hours if a sustained release preparation has been taken.

Haemodialysis serves no purpose as nifedipine is not dialysable, but plasmapheresis is advisable (high plasma protein binding, relatively low volume of distribution).

Hypotension as a result of cardiogenic shock and arterial vasodilatation can be treated with calcium (10-20 ml of a 10 % calcium gluconate solution administered intravenously over 5-10 minutes). If the effects are inadequate, the treatment can be continued, with ECG monitoring. If an insufficient increase in blood pressure is achieved with calcium, vasoconstricting sympathomimetics such as dopamine or noradrenaline should be administered. The dosage of these drugs should be determined by the patient’s response.

Symptomatic bradycardia may be treated with atropine, beta-sympathomimetics or a temporary cardiac pacemaker, as required (in life-threatening bradycardiac disturbances of heart rhythm).

Additional fluids should be administered with caution to avoid cardiac overload.

3 years.

Store below 25°C in the original package, in order to protect from light and moisture.

White polyvinylchloride film – aluminium foil blisters of ten tablets. Packs, with a patient information leaflet, containing 20, 30 or 50 tablets are available.

Not all pack sizes may be marketed.

No special requirements for disposal.