BMA Concise Guide to Medicine & Drugs

Felodipine

Brand names Cardioplen, Felotens, Keloc, Parmid, Plendil, Vascalpha

Used in the following combined preparation Triapin

QUICK REFERENCE

Drug group Anti-angina drug and antihypertensive drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Felodipine belongs to a group of drugs known as calcium channel blockers. It is used either alone or with another antihypertensive, such as an ACE Inhibitor or a diuretic, in the treatment of hypertension (high blood pressure). It may be used alone or with a beta blocker in the treatment of angina.

The drug works by relaxing the lining of the muscles in small blood vessels, dilating them. This enables blood to be pumped more easily throughout the body, thereby lowering blood pressure and reducing the strain on the heart.

Felodipine is not usually prescribed to people with unstable angina or uncontrolled heart failure. It is prescribed with caution to people whose liver function is impaired.

As with other drugs of its class, felodipine may cause the blood pressure to fall too low at the start of treatment.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, MR-tablets.

Frequency and timing of doses Once daily, in the morning, swallowed whole with at least half a glass of water; do not chew or crush.

Adult dosage range Hypertension 5mg (2.5mg for elderly people) daily (initial dose), increased to 10mg daily (maintenance dose). Angina 5mg daily, increased to 10mg if needed.

Onset of effect 1–2 hours.

Duration of action 24 hours.

Diet advice Felodipine should not be taken with grapefruit juice.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. Take the next dose as scheduled. Do not take an extra dose to make up.

Stopping the drug Do not stop taking the drug without consulting your doctor. Stopping abruptly may worsen the underlying condition.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause dizziness or collapse. Notify your doctor urgently.

POSSIBLE ADVERSE EFFECTS

Flushing, headache, palpitations, and fatigue are common side effects of felodipine. They are usually transient and are most likely to occur at the start of treatment or after an increase in dosage. Other common side effects include dizziness (which may be due to excessively lowered blood pressure), ankle swelling, and tinnitus. Discuss with your doctor if any of these are severe. More rarely, felodipine may cause gingivitis or worsening of angina; if so, consult your doctor.

INTERACTIONS

Other antihypertensives may increase felodipine’s blood-pressure-lowering effects.

Erythromycin, itraconazole, ketoconazole, atazanavir, and ritonavir may increase the effects of felodipine.

Antiepileptics may reduce the effectiveness of felodipine.

Ciclosporin, tacrolimus, and theophylline/aminophylline Toxicity of these drugs may be increased with felodipine.

Grapefruit juice may block the breakdown of felodipine, increasing its effects.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have liver problems.

· You have angina.

· You have had a recent heart attack.

· You have heart problems, especially aortic stenosis.

· You have lactose intolerance.

· You are taking other medicines.

Pregnancy Not prescribed. May cause defects in the unborn baby.

Breast-feeding Not recommended. The drug passes into the breast milk and may affect the baby adversely.

Infants and children Not recommended. Safety not established.

Over 60 Increased likelihood of adverse effects. Reduced dose may therefore be necessary.

Driving and hazardous work Do not undertake such activities until you have learned how felodipine affects you because the drug can cause dizziness.

Alcohol Avoid. Alcohol may increase dizziness and the blood-pressure-lowering effect of felodipine, especially at the start of treatment.

PROLONGED USE

No problems expected.