What is Amlodipine Tablets ?
Amlodipine is a medication primarily used to treat high blood pressure (hypertension) and certain types of chest pain (angina). It belongs to a class of drugs known as calcium channel blockers. Amlodipine works by relaxing and widening the blood vessels, making it easier for the heart to pump blood.
Amlodipine Tablets Uses
- Hypertension (High Blood Pressure): Amlodipine helps relax and widen the blood vessels, which makes it easier for the heart to pump blood. This, in turn, lowers blood pressure.
- Stable Angina: It can be used to treat stable angina, a type of chest pain that occurs when the heart doesn’t get enough blood flow and oxygen, often during physical activity or stress.
- Vasospastic Angina (Prinzmetal’s Angina): Amlodipine can also be used to treat vasospastic angina, a less common type of chest pain caused by a spasm in the coronary arteries.
Amlodipine Tablets – Mechanism of Action and Pharmacology
Mechanism of Action:
- Calcium Channel Blockade: Amlodipine works by blocking the influx of calcium ions into the smooth muscle cells of the heart and blood vessels. It does this by specifically targeting L-type calcium channels. By inhibiting these channels, amlodipine reduces the amount of calcium available for muscle contraction.
- Vasodilation: By decreasing the calcium levels in smooth muscle cells, amlodipine causes relaxation (dilation) of the arterial blood vessels. This results in a reduction in peripheral vascular resistance, which makes it easier for the heart to pump blood against less resistance. As a result, blood pressure is lowered.
Pharmacology:
- Absorption: Amlodipine is taken orally, and it is well-absorbed from the gastrointestinal tract. It reaches peak blood concentrations within 6-12 hours after ingestion.
- Distribution: It is highly protein-bound (approximately 97-99%) in the bloodstream. This means that most of the drug is attached to proteins and is not freely circulating.
- Metabolism: Amlodipine is primarily metabolized by the liver through a process called hepatic metabolism. The main metabolite formed is inactive and is excreted in the urine.
- Elimination: The elimination half-life of amlodipine is relatively long, about 35-50 hours. This means it takes a significant amount of time for the drug to be cleared from the body.
- Excretion: Amlodipine and its metabolites are primarily excreted in the urine.
- Onset and Duration of Action: The onset of action is relatively slow, and it may take a few hours to start working. However, its effects can last for up to 24 hours, which allows for once-daily dosing.
Amlodipine Tablets – Composition and Active Ingredients
Amlodipine tablets typically contain amlodipine besylate as the active ingredient. Amlodipine besylate is a white or almost white crystalline powder that is slightly soluble in water and sparingly soluble in ethanol. It is a calcium channel blocker that works by inhibiting the influx of calcium ions into smooth muscle cells, leading to vasodilation and a reduction in blood pressure.
In addition to amlodipine besylate, the tablets may also contain various inactive ingredients that serve as fillers, binders, stabilizers, and sometimes colorants or flavorings. The specific formulation of amlodipine tablets can vary between different pharmaceutical manufacturers and brands.
Common inactive ingredients in amlodipine tablets may include:
- Microcrystalline Cellulose: This is a commonly used filler and binder in pharmaceuticals. It helps give the tablet its structure.
- Lactose Monohydrate: Lactose is a sugar commonly used in tablet formulations as a filler and to help with tablet disintegration.
- Magnesium Stearate: This is a lubricant that helps prevent the tablet components from sticking to the manufacturing equipment.
- Sodium Starch Glycolate: This is a disintegrant, which helps the tablet break apart and release the active ingredient in the digestive system.
- Hypromellose: This is a semisynthetic polymer used as a coating for the tablet. It can provide protection, control release of the drug, and aid in swallowing.
- Titanium Dioxide (Colorant): This is a white pigment often used to give tablets a consistent color.
- Polyethylene Glycol: Sometimes used as a binding agent, this compound helps to hold the tablet together.
Amlodipine Tablets – Side-effects
- Peripheral Edema: Swelling of the ankles, feet, and legs due to fluid retention.
- Headache: Some people may experience mild to moderate headaches.
- Dizziness or Lightheadedness: This may occur, especially when standing up quickly. It’s more common when starting the medication or when the dose is increased.
- Flushing or Warmth: Some individuals may experience a feeling of warmth, particularly in the face.
- Fatigue: Feeling tired or lacking energy is a possible side effect.
- Palpitations: Some individuals may experience awareness of their heartbeat, but this is less common.
- Nausea or Stomach Upset: This can occur, although it’s not very common.
- Muscle Cramps or Weakness: In rare cases, amlodipine may lead to muscle-related symptoms.
- Constipation: Some people may experience mild constipation.
