Amlodipine: Uses, Indications, Dosages, Precautions, Contraindications, Side Effects & Interactions

Amlodipine

(am-loe-di-peen)
Classification 
Pharmacotherapeutic: Calcium channel blocker
Clinical: Antihypertensive, antianginal

Apo-AmLODIPine

Norvasc

CATEGORY AND SCHEDULE

Pregnancy Risk Category: C

Do not confuse:

amLODIPine with aMILoride, or Norvasc with Navane or Vascor

General Information

Amlodipine belongs to a group of medicines known as calcium channel blockers, which interfere with the conduction of signals in the muscles of the heart and blood vessels. Amlodipine is used in the treatment of angina to help prevent chest pain attacks. Unlike other angina medications (such as beta blockers), it can be used safely by people with asthma and people with diabetes who require insulin. Amlodipine is also used to lower high blood pressure (hypertension). Like other drugs in its class, amlodipine can lower blood pressure too much at the start of treatment. In rare cases, angina may worsen at the start of treatment with amlodipine

Amlodipine can cause severe reactions such as: overdose can cause excessive peripheral vasodilation, marked hypotension with reflex tachycardia, syncope

Action

It inhibits the entry of calcium ion through the cell membrane during cardiac depolarization; produces relaxation of coronary vascular smooth muscle and peripheral vascular smooth muscle; dilates the coronary vascular arteries; increases myocardial oxygen supply in patients with vasospastic angina

Therapeutic Effect

It dilates the coronary arteries, peripheral arteries / arterioles. Decreases total peripheral vascular resistance and BP due to vasodilation

Availability (Rx)

Tablets: 2.5 mg, 5 mg, 10 mg

Uses

Chronic stable angina pectoris, hypertension, variant angina (Prinzmetal’s angina); may coadminister with other antihypertensives, antianginals

Unlabeled uses: Hypertension (pediatric patients)

Precautions

Pregnancy C, breastfeeding, children, geriatric, CHF, hypotension, hepatic injury, GERD

Black Box Warning: Hypersensitivity to dihydropyridine

Make sure to tell your doctor if:

• You have long-term liver problems.

• You have heart failure or aortic stenosis.

• You have diabetes.

• You are taking other medicines

Indications and Dosages

‣ To Treat Hypertension

PO

• Adults: Initially, 5 mg/day as a single dose. Maximum: 10 mg/day

• Elderly and Debilitated Patients: Initially, 2.5 mg/day as a single dose. Titrate to 5 mg/day if needed

• Children 6-17 yr: 2.5-5 mg/day as a single dose

‣ To Treat Coronary artery disease

PO

• Adult: 5-10 mg/day

• Geriatric: 5 mg/day, max 10 mg/day

• Eldery, patients with hepatic insufficiency: 5 mg/day as a single dose

‣ To treat angina (chronic stable or vasospastic) and Prinzmetal’s (variant) angina

PO

• Adults: 5-10 mg/day as a single dose

• Elderly: 5 mg/day as a single dose. Maximum: 10 mg

‣ Dosage in hepatic impairment

PO

• For adults and elderly patients, give 2.5 mg/day for hypertension; 5 mg/day for angina

‣ Dosage in Renal Impairment

• No dose adjustment

Pharmacokinetics

Slowly absorbed from the GI tract. Protein binding: 93%. Extensively metabolized in the liver; active drug and metabolites excreted primarily in urine. Not removed by hemodialysis. Half-life: 30-50 h (increased in elderly patients and in those with liver cirrhosis)

Implementation

PO route

• Give once a day, without regard to meals

Contraindications

Severe hypotension, known sensitivity to amlodipine

Cautions: Hepatic impairment, severe aortic stenosis, hypertrophic cardiomyopathy with outflow tract obstruction

Interactions

Individual drugs

• Alcohol, fentaNYL, quiNIDine: increased hypotension

• Diltiazem: increased amLODIPine level

• Lithium: increased neurotoxicity

Drug classifications

• Antihypertensives, nitrates: increased hypotension

• NSAIDs: decreased antihypertensive effect

Drug/laboratory tests

• May increase hepatic enzyme levels

Drugs/food

• Grapefruit products may increase concentration, hypotensive effects

Herbal

• St. John’s wort may decrease concentration

• Ephedra, yohimbe may worsen hypertension

• Garlic may increase antihypertensive effect

Side effects

• CNS: Anxiety, dizziness, fatigue, headache, lethargy, light-headedness, paresthesia, somnolence, syncope, tremor

• CV: Arrhythmias, hypotension, palpitations, peripheral edema

• EENT: Dry mouth, pharyngitis

• ENDO: Hot flashes

• GI: Abdominal cramps, abdominal pain, constipation, diarrhea, esophagitis, indigestion, nausea

• GU: Decreased libido, impotence, urinary frequency

• MS: Myalgia

• RESP: Dyspnea

• SKIN: Dermatitis, flushing, rash

• Other: Weight loss

 

Nursing considerations

Baseline assessment

• Assess baseline renal/hepatic function tests, B/P, apical pulse

Intervention/evaluation

• Assess B/P (if systolic B/P is less than 90 mm Hg, withhold medication, contact

physician)

• Assess for peripheral edema behind medial malleolus (sacral area in

bedridden pts)

• Assess skin for flushing. Question for headache, asthenia

Equipment must be available for anaphylaxis

• Assess fluid volume status: distended red veins, crackles in lung; color, quality, and specific gravity of urine, skin turgor, adequacy of pulses, moist mucous membranes, bilateral lung sounds, peripheral pitting edema; dehydration symptoms of decreasing output, thirst, hypotension, dry mouth and mucous membranes should be reported

• Assess for angina: intensity, location, duration of pain

• Monitor B/P and pulse; if B/P drops, call prescriber

• Monitor ALT, AST, bilirubin daily; if these are elevated, hepatotoxicity is suspected

• Monitor platelet count: if ,150,000/mm3, product is usually discontinued and another product started

• Monitor cardiac status: B/P, pulse, respiration, ECG

Evaluation

Positive therapeutic result

• Decreased anginal pain

• Decreased B/P

• Increased exercise tolerance

Patient/family teaching

• Tell patient to Do not abruptly discontinue medication

• Tell patient to Compliance with therapy regimen is essential to control hypertension

• Tell patient to take missed dose as soon as remembered and next dose in 24 hours

• Tell patient to immediately notify prescriber of dizziness, arm or leg swelling, difficulty breathing, hives, or rash

• Instruct patient to avoid alcohol and OTC products unless directed by prescriber

• Advise patient to comply in all areas of medical regimen: diet, exercise, stress reduction, smoking cessation, product therapy; to notify prescriber of irregular heartbeat, shortness of breath, swelling of feet, face, and hands, severe dizziness, constipation, nausea, hypotension; use nitroglycerin when angina is severe

• Teach patient to use as directed even if feeling better; may be taken with other cardiovascular products (nitrates, b-blockers)

• Suggest taking amlodipine with food to reduce GI upset

• Advise patient to routinely have blood pressure checked for possible hypotension

• Inform patient to Avoid tasks that require alertness, motor skills until response to drug is established

• Tell patient to Do not ingest grapefruit products or alcohol

Treatment of Overdose:

Defibrillation, b-agonists, IV calcium inotropic agents, diuretics, atropine for AV block, vasopressor for hypotension