DIGNOKONSTANT TABLETS 10MG

Indications

• Hypertension
• Angina pectoris
• Raynaud's phenomenon
• Vasospastic disorders

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines in paediatric patients.

Adults: Refer to the BNF for specific dosing information, as doses may vary based on the condition being treated and patient response.

Mechanism of action

Nifedipine selectively inhibits L-type calcium channels on vascular smooth muscle cells. By blocking these channels, nifedipine decreases intracellular calcium concentrations, leading to relaxation of smooth muscle and vasodilation of peripheral and coronary arteries.

Pharmacodynamics

The vasodilatory effects of nifedipine lead to a reduction in systemic vascular resistance and arterial pressure, which can help alleviate symptoms of angina by decreasing myocardial oxygen demand. The onset of action is typically within 20 minutes to 1 hour after administration, with a duration of effect that can last for several hours, depending on the formulation used.

Pharmacokinetics

Nifedipine is well absorbed after oral administration, with peak plasma concentrations occurring approximately 30 minutes to 2 hours post-dose. It undergoes extensive first-pass metabolism in the liver, resulting in a variable bioavailability. The drug is highly protein-bound, primarily to albumin, and is metabolized by cytochrome P450 enzymes, particularly CYP3A4. The elimination half-life is approximately 2 to 5 hours, and the drug is excreted mainly in urine as metabolites.

Contra-indications

• Severe hypotension
• Cardiogenic shock
• Acute myocardial infarction
• Unstable angina
• Severe aortic stenosis
• Hypersensitivity to nifedipine or any of its components

Adverse effects

• Flushing
• Headache
• Dizziness
• Palpitations
• Peripheral edema
• Gingival hyperplasia
• Nausea
• Constipation
• Fatigue

Interactions

• CYP3A4 inhibitors may increase nifedipine plasma concentrations
• CYP3A4 inducers may decrease nifedipine plasma concentrations
• Concurrent use with beta-blockers may increase the risk of heart failure
• Other antihypertensive agents may have additive effects

Precautions

• Use with caution in patients with hepatic impairment
• Monitor blood pressure and heart rate regularly
• Caution in patients with heart failure
• Consider risks in elderly patients or those with comorbidities

Pregnancy

Nifedipine is categorized as a pregnancy category C drug. Its use should be carefully considered, weighing potential benefits against risks.

Breast-feeding

Nifedipine is excreted in breast milk. Caution is advised when administered to nursing mothers.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Extended-release capsules
• Immediate-release capsules
• Tablets