Nifedipine

Absorption

Sublingual dosing leads to a Cmax of 10ng/mL, with a Tmax of 50min, and an AUC of 25ng*h/mL. Oral dosing leads to a Cmax of 82ng/mL, with a Tmax of 28min, and an AUC of 152ng*h/mL.
Nifedipine is a Biopharmaceutics Classification System Class II drug, meaning it has low solubility and high intestinal permeability. It is almost completely absorbed in the gastrointestinal tract but has a bioavilability of 45-68%, partly due to first pass metabolism.

Toxicity

The oral LD50 in rats is 1022mg/kg and in mice is 202mg/kg.
Patients experiencing an overdose may present with hypotension, sinus node dysfunction, atrioventricular node dysfunction, and reflex tachycardia. Overdose may be managed by monitoring cardiovascular and respiratory function; elevating extremities; and administering vasopressors, fluids, and calcium infusions.

Description

Nifedipine (21829-25-4) is a clinically useful L-type calcium blocker.

The Uses of Nifedipine

Nifedipine is used for preventing and relieving angina pectoris attacks, for hypertension, and as an ingredient in combination therapy for chronic cardiac insufficiency.

Indications

Nifedipine capsules are indicated to treat vasospastic angina and chronic stable angina. Extended release tablets are indicated to treat vasospastic angina, chronic stable angina, and hypertension.

Background

Nifedipine, or BAY a 1040, is a first generation dihydropyridine L-type calcium channel blocker, similar to nicardipine. Nifedipine was developed by Bayer and first described in the literature, along with other dihydropyridines, in 1972. Since nifedipine's development, second and third generation dihydropyridines have been developed with slower onsets and longer durations of action. The most popular of the third generation dihydropyridines is amlodipine.
Nifedipine was granted FDA approval on 31 December 1981.

What are the applications of Application

Nifedipine is a selective calcium channel protein inhibitor

Pharmacokinetics

Nifedipine is an inhibitor of L-type voltage gated calcium channels that reduces blood pressure and increases oxygen supply to the heart. Immediate release nifedipine's duration of action requires dosing 3 times daily. Nifedipine dosing is generally 10-120mg daily. Patients should be counselled regarding the risk of excessive hypotension, angina, and myocardial infarction.

Metabolism

Nifedipine is predominantly metabolized by CYP3A4. Nifedipine is predominantly metabolized to 2,6-dimethyl-4-(2-nitrophenyl)-5-methoxycarbonyl-pyridine-3-carboxylic acid, and then further metabolized to 2-hydroxymethyl-pyridine carboxylic acid. Nifedipine is also minorly metabolized to dehydronifedipine.