Amlodipine

Amlodipine is a calcium channel blocker (calcium antagonist) of the dihydropyridine type. It is used to treat high blood pressure and chronic stable angina pectoris.

Amlodipine is characterized by a particularly long half-life (35-50 hours). The active ingredient is available as a single-ingredient product and in numerous combinations: with valsartan (Exforge®, Dafiro®), with olmesartan (Sevikar), with ramipril (Ramipril HEXAL® plus Amlodipin) and in triple combinations with sartans and HCT (e.g., Vocado® HCT).

Amlodipine is available as a generic from numerous manufacturers.

Amlodipine blocks voltage-dependent L-type calcium channels:

Mechanism of action:

• Blocks the influx of calcium into the smooth muscle of the blood vessels
• The vascular muscle cells can no longer contract
• Arteries and arterioles dilate
• Peripheral vascular resistance decreases
• Blood pressure falls

Special features:

• Acts mainly on the blood vessels (not on the heart)
• No relevant lowering of the heart rate
• No effect on electrical conduction in the heart
• Very long half-life (35-50 hours)
• Steady drug levels without peaks and troughs

In angina pectoris:

• Dilates the coronary arteries
• Improves blood flow to the heart muscle
• Reduces oxygen consumption by lowering afterload

Onset of action: Slow, steady onset of action over 6-12 hours. Stable blood pressure reduction after 7-14 days. No risk of reflex tachycardia, as there is with fast-acting calcium channel blockers.

Amlodipine is suitable for:

• Adults with high blood pressure
• Chronic stable angina pectoris
• Vasospastic angina (Prinzmetal angina)

Especially recommended for:

• Isolated systolic hypertension (especially older patients)
• High blood pressure in dark-skinned patients (better response)
• Angina pectoris with high blood pressure
• In combination with ACE inhibitors or sartans

Not suitable:

• Severe aortic stenosis
• Unstable angina pectoris
• Cardiogenic shock
• Severe hypotension
• Pregnancy (use only if no safer treatment alternatives are available and the disease poses a higher risk to mother and unborn child)

High blood pressure:

• Starting dose: 5 mg once daily
• Usual maintenance dose: 5-10 mg once daily
• Maximum dose: 10 mg daily

Angina pectoris:

• 5-10 mg once daily

Older patients / liver impairment:

• Starting dose: 2.5-5 mg once daily

Available strengths:

• 5 mg, 10 mg tablets

Combination products:

• Amlodipine + valsartan (Exforge®, Dafiro®)
• Amlodipine + olmesartan (Sevikar)
• Amlodipine + ramipril (Ramipril HEXAL® plus Amlodipin)
• Amlodipine + valsartan + HCT (Exforge HCT®)
• Amlodipine + olmesartan + HCT (Vocado® HCT)

How to take:

• Once daily, always at the same time of day
• Regardless of meals
• Swallow with enough water
• Can be taken in the morning or in the evening

Dose adjustment:

• Start with 5 mg
• Increase to 10 mg after 2-4 weeks if needed
• No gradual dose build-up needed (slow onset of action)

Important information:

• No abrupt discontinuation needed (long half-life)
• Avoid grapefruit juice (slightly increases amlodipine levels)
• Ankle swelling is common but harmless
• If your gums become swollen, inform your dentist

Amlodipine must not be taken in cases of:

• Hypersensitivity to amlodipine or other dihydropyridines
• Severe hypotension (systolic below 90 mmHg)
• Cardiogenic shock
• Severe aortic stenosis
• Unstable angina pectoris (except Prinzmetal angina)
• Acute heart attack (first 4 weeks)

Use with caution in:

• Heart failure (NYHA III-IV)
• Liver impairment (slower breakdown)
• Older patients (lower starting dose)

Pregnancy: Not recommended. Animal studies showed evidence of reproductive toxicity. Alternative blood pressure medications (e.g., methyldopa) should be preferred.

Very common (more than 10%):

• Ankle edema (dose-dependent, up to 10-15% at 10 mg)

Common (1-10%):

• Headache
• Facial redness (flushing)
• Tiredness, drowsiness
• Dizziness
• Palpitations
• Gastrointestinal complaints

Uncommon (0.1-1%):

• Mood swings, sleep disturbances
• Tremor
• Visual disturbances
• Skin rash, itching
• Muscle cramps

Rare:

• Allergic reactions
• Elevated liver enzymes
• Heart rhythm disturbances

Very rare:

• Gum swelling (gingival hyperplasia)

Ankle edema: The most common side effect. It is caused by dilated arteries while the veins are not dilated (this is not heart failure). Combining amlodipine with an ACE inhibitor or sartan can significantly reduce the edema.

Use caution when taking at the same time as:

• Strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) → increased amlodipine levels
• CYP3A4 inducers (rifampicin, St. John's wort) → reduced effect
• Simvastatin → limit dose to max. 20 mg
• Ciclosporin → increased ciclosporin levels
• Tacrolimus → increased tacrolimus levels
• Other blood pressure-lowering drugs → increased hypotension

Grapefruit: Grapefruit juice can inhibit the breakdown of amlodipine and slightly increase its effect. Moderate consumption is generally not a problem, but regular consumption of large amounts should be avoided.