Tiapamil

A calcium channel blocker used in the treatment of cardiovascular diseases

Tiapamil
File:Tiapamil.png
INN
Drug class
Routes of administration	Oral
Pregnancy category
Bioavailability	40%
Metabolism	Hepatic
Elimination half-life	3-4 hours
Excretion	Renal
Legal status	Rx-only
CAS Number
PubChem
DrugBank
ChemSpider
KEGG

Tiapamil is a calcium channel blocker that is primarily used in the management of cardiovascular diseases. It is a member of the phenylalkylamine class of calcium channel blockers, similar to verapamil.

Pharmacology

Tiapamil functions by inhibiting the influx of calcium ions through L-type calcium channels in the cardiac muscle and vascular smooth muscle. This action results in the relaxation of vascular smooth muscle, leading to a decrease in vascular resistance and blood pressure. Additionally, it reduces the force of contraction of the heart, which can be beneficial in conditions such as angina pectoris and hypertension.

Clinical Uses

Tiapamil is used in the treatment of various cardiovascular conditions, including:

• Hypertension: By reducing peripheral vascular resistance, tiapamil helps lower blood pressure.
• Angina pectoris: It decreases myocardial oxygen demand by reducing heart rate and contractility.
• Arrhythmias: Tiapamil can be used to manage certain types of cardiac arrhythmias due to its effects on cardiac conduction.

Side Effects

Common side effects of tiapamil include:

• Dizziness
• Headache
• Nausea
• Constipation

Less common but more serious side effects may include:

• Bradycardia
• Hypotension
• Heart failure

Mechanism of Action

Tiapamil blocks the L-type calcium channels in the heart and blood vessels. This blockade prevents calcium from entering cells, which is necessary for muscle contraction. By inhibiting calcium entry, tiapamil causes relaxation of the vascular smooth muscle and decreases the contractility of the heart muscle.

Pharmacokinetics

Tiapamil is administered orally and has a bioavailability of approximately 40% due to first-pass metabolism in the liver. It is highly protein-bound (90%) and is metabolized hepatically. The elimination half-life of tiapamil is between 3 to 4 hours, and it is excreted primarily through the kidneys.

Related pages

• Calcium channel blocker
• Verapamil
• Hypertension
• Angina pectoris