bit pups are strikingly similar to those seen in pups exposed to phenytoin, and these are in turn similar to the phalangeal deformities that are the most common malformation seen in human children with in utero exposure to phenytoin.
From the clinical evidence available, a specific prenatal risk has not been identified. However, an increase in perinatal asphyxia, caesarean delivery, prematurity and intrauterine growth retardation have been reported.
Careful monitoring of blood pressure must be exercised in pregnant women, when administering nifedipine in combination with IV magnesium sulfate due to the possibility of an excessive fall in blood pressure which could harm the mother and fetus.
There are no adequate and well controlled studies in pregnant women.
Nursing Mothers
Nifedipine is excreted in human milk. Nursing mothers are advised not to breast-feed their babies when taking the drug.
Pediatric Use
The safety and effectiveness of nifedipine extended-release tablets in pediatric patients have not been established.
Geriatric Use
Although small pharmacokinetic studies have identified an increased half-life and increased Cmax and AUC (See CLINICAL PHARMACOLOGY: Pharmacokinetics and Metabolism), clinical studies of nifedipine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
ADVERSE REACTIONS
The incidence of adverse events during treatment with nifedipine extended-release tablets in doses up to 90 mg daily were derived from multicenter placebo-controlled clinical trials in 370 hypertensive patients. Atenolol 50 mg once daily was used concomitantly in 187 of the 370 patients on nifedipine extended-release tablets and in 64 of the 126 patients on placebo. All adverse events reported during nifedipine extended-release tablets therapy were tabulated independently of their causal relationship to medication.
The most common adverse event reported with nifedipine extended-release tablets was peripheral edema. This was dose related and the frequency was 18% on nifedipine extended-release tablets 30 mg daily, 22% on nifedipine extended-release tablets 60 mg daily and 29% on nifedipine extended-release tablets 90 mg daily versus 10% on placebo.
Other common adverse events reported in the above placebo-controlled trials include:
Nifedipine Extended-release Tablets (%)
(n = 370) Placebo (%)
(n = 126)
Adverse Event
Headache 19 13
Flushing/heat sensation 4 0
Dizziness 4 2
Fatigue/asthenia 4 4
Nausea 2 1
Constipation 1 0
Where the frequency of adverse events with nifedipine extended-release tablets and placebo is similar, causal relationship cannot be established.
The following adverse events were reported with an incidence of 3% or less in daily doses up to 90 mg:
Body as a Whole/Systemic: chest pain, leg pain
Central Nervous System: paresthesia, vertigo
Dermatologic: rash
Gastrointestinal: constipation
Musculoskeletal: leg cramps
Respiratory: epistaxis, rhinitis
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