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Related to Calan: calendar, clan, verapamil


trademark for preparations of verapamil hydrochloride, a calcium channel blocking agent used to treat angina pectoris, hypertension, and tachyarrhythmias.


(ver-ap-a-mil) ,


(trade name),

Calan SR

(trade name),

Isoptin SR

(trade name),


(trade name),

Verelan PM

(trade name)


Therapeutic: antianginals
Pharmacologic: calcium channel blockers
Pregnancy Category: C


Management of hypertension, angina pectoris, and/or vasospastic (Prinzmetal’s) angina.Management of supraventricular arrhythmias and rapid ventricular rates in atrial flutter or fibrillation.Prevention of migraine headache.


Inhibits the transport of calcium into myocardial and vascular smooth muscle cells, resulting in inhibition of excitation-contraction coupling and subsequent contraction.
Decreases SA and AV conduction and prolongs AV node refractory period in conduction tissue.

Therapeutic effects

Systemic vasodilation resulting in decreased BP.
Coronary vasodilation resulting in decreased frequency and severity of attacks of angina.
Reduction of ventricular rate during atrial fibrillation or flutter.


Absorption: 90% absorbed after oral administration, but much is rapidly metabolized, resulting in bioavailability of 20–25%.
Distribution: Small amounts enter breast milk.
Protein Binding: 90%.
Metabolism and Excretion: Mostly metabolized by the liver (primarily by CYP3A4).
Half-life: 4.5–12 hr.

Time/action profile (cardiovascular effects)

PO1–2 hr30–90 min†3–7 hr
PO-ERunknown5–7 hr24 hr
IV1–5 min‡3–5 min2 hr‡
†Single dose; effects from multiple doses may not be evident for 24–48 hr.‡Antiarrhythmic effects; hemodynamic effects begin 3–5 min after injection and persist for 10–20 min.


Contraindicated in: Hypersensitivity;Sick sinus syndrome;2nd- or 3rd-degree AV block (unless an artificial pacemaker is in place);Systolic BP <90 mm Hg;HF, severe ventricular dysfunction, or cardiogenic shock, unless associated with supraventricular tachyarrhythmias;Concurrent IV beta blocker therapy.
Use Cautiously in: Severe hepatic impairment (dose ↓ recommended);History of serious ventricular arrhythmias or HF; Geriatric: Dose ↓/slower IV infusion rates recommended (↑ risk of hypotension); Obstetric / Lactation: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • abnormal dreams
  • anxiety
  • confusion
  • dizziness/lightheadedness
  • drowsiness
  • extrapyramidal reactions
  • headache
  • jitteriness
  • nervousness
  • psychiatric disturbances
  • weakness

Ear, Eye, Nose, Throat

  • blurred vision
  • disturbed equilibrium
  • epistaxis
  • tinnitus


  • cough
  • dyspnea
  • shortness of breath


  • arrhythmias (life-threatening)
  • hf (life-threatening)
  • bradycardia
  • chest pain
  • hypotension
  • palpitations
  • peripheral edema
  • syncope
  • tachycardia


  • ↑ liver enzymes
  • anorexia
  • constipation
  • diarrhea
  • dry mouth
  • dysgeusia
  • dyspepsia
  • nausea
  • vomiting


  • dysuria
  • nocturia
  • polyuria
  • sexual dysfunction
  • urinary frequency


  • stevens-johnson syndrome (life-threatening)
  • dermatitis
  • erythema multiforme
  • flushing
  • photosensitivity
  • pruritus/urticaria
  • rash
  • sweating


  • gynecomastia
  • hyperglycemia


  • anemia
  • leukopenia
  • thrombocytopenia


  • weight gain


  • joint stiffness
  • muscle cramps


  • paresthesia
  • tremor


  • gingival hyperplasia


Drug-Drug interaction

Additive hypotension may occur when used concurrently with fentanyl, other antihypertensives, nitrates, acute ingestion of alcohol, or quinidine.Antihypertensive effects may be ↓ by concurrent use of NSAIDs.Serum digoxin levels may be ↑.Concurrent use with beta blockers, digoxin, disopyramide, clonidine, or phenytoin may result in bradycardia, conduction defects, or HF.↑ risk of hypotension and bradycardia with erythromycin, clarithromycin, telithromycin, or ritonavir.May ↓ metabolism of and ↑ risk of toxicity from cyclosporine, prazosin, quinidine, or carbamazepine.May ↓ effectiveness of rifampin.↑ the muscle-paralyzing effects of nondepolarizing neuromuscular-blocking agents.Effectiveness may be ↓ by coadministration with vitamin D compounds and calcium.May alter serum lithium levels.May ↑ doxorubicin and paclitaxel levels.May ↑ risk of bleeding with aspirin.↑ caffeine levels with caffeine-containing herbs (cola nut, guarana, mate, tea, coffee).Grapefruit juice ↑ serum levels and effect.


Oral (Adults) 80–120 mg 3 times daily, ↑ as needed. Patients with hepatic impairment or geriatric patients—40 mg 3 times daily initially. Extended-release preparations—120–240 mg/day as a single dose; may be ↑ as needed (range 240–480 mg/day).
Oral (Children up to 15 yr) 4–8 mg/kg/day in divided doses.
Intravenous (Adults) 5–10 mg (75–150 mcg/kg); may repeat with 10 mg (150 mcg/kg) after 15–30 min.
Intravenous (Children 1–15 yr) 2–5 mg (100–300 mcg/kg); may repeat after 30 min (initial dose not to exceed 5 mg; repeat dose not to exceed 10 mg).
Intravenous (Children <1 yr) 0.75–2 mg (100–200 mcg/kg); may repeat after 30 min.

Availability (generic available)

Tablets: 40 mg, 80 mg, 120 mg Cost: Generic — 40 mg $21.85 / 100, 80 mg $10.83 / 100
Extended-release tablets (Isoptin SR): 120 mg, 180 mg, 240 mg Cost: Generic — 120 mg $31.44 / 100, 180 mg $35.98 / 100, 240 mg $27.80 / 100
Extended-release capsules (Verelan PM): 100 mg, 200 mg, 300 mg Cost: Generic — 100 mg $195.84 / 100, 200 mg $252.23 / 100, 300 mg $366.98 / 100
Extended-release capsules (Verelan): 120 mg, 180 mg, 240 mg, 360 mg Cost: Generic — 120 mg $130.25 / 100, 180 mg $135.16 / 100, 240 mg $152.54 / 100, 360 mg $209.94 / 100
Solution for injection: 2.5 mg/mL
In combination with: trandolapril (Tarka); see combination drugs.

Nursing implications

Nursing assessment

  • Monitor BP and pulse before therapy, during dosage titration, and periodically throughout therapy. Monitor ECG periodically during prolonged therapy. Verapamil may cause prolonged PR interval.
    • Monitor intake and output ratios and daily weight. Assess for signs of HF (peripheral edema, rales/crackles, dyspnea, weight gain, jugular venous distention).
    • Patients receiving digoxin concurrently with calcium channel blockers should have routine serum digoxin levels and be monitored for signs and symptoms of digoxin toxicity.
  • Assess for rash periodically during therapy. May cause Stevens-Johnson syndrome. Discontinue therapy if severe or if accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.
  • Angina: Assess location, duration, intensity, and precipitating factors of patient’s anginal pain.
  • Arrhythmias: Monitor ECG continuously during administration. Notify health care professional promptly if bradycardia or prolonged hypotension occurs. Emergency equipment and medication should be available. Monitor BP and pulse before and frequently during administration.
  • Lab Test Considerations: Total serum calcium concentrations are not affected by calcium channel blockers.
    • Monitor serum potassium periodically. Hypokalemia ↑ risk of arrhythmias and should be corrected.
    • Monitor renal and hepatic functions periodically during long-term therapy. May cause ↑ hepatic enzymes after several days of therapy, which return to normal on discontinuation of therapy.

Potential Nursing Diagnoses

Decreased cardiac output (Indications)
Acute pain (Indications)


  • Oral: Administer verapamil with meals or milk to minimize gastric irritation.
    • Do not open, crush, break, or chew sustained-release capsules or tablets. Empty tablets that appear in stool are not significant.
  • Intravenous Administration
  • Intravenous: Patients should remain recumbent for at least 1 hr after IV administration to minimize hypotensive effects.
  • Diluent: Administer undiluted.Concentration: 2.5 mg/mL.
  • Rate: Administer over 2 min. Geriatric: Administer over 3 min.
  • Y-Site Compatibility: alemtuzumab, alfentanil, amikacin, aminocaproic acid, amphotericin B lipid complex, anidulafungin, argatroban, ascorbic acid, atracurium, atropine, aztreonam, benztropine, bivalirudin, bleomycin, bumetanide, buprenorphine, butorphanol, calcium chloride, calcium gluconate, carboplatin, carmustine, caspofungin, cefazolin, cefotaxime, cefotetan, cefoxitin, ceftriaxone, cefuroxime, chlorpromazine, ciprofloxacin, cisplatin, clindamycin, cyanocobalamin, cyclophosphamide, cyclosporine, cytarabine, dactinomycin, daptomycin, dexamethasone, dexmedetomidine, dexrazoxane, digoxin, diltiazem, diphenhydramine, dobutamine, docetaxel, dolasetron, dopamine, doxorubicin hydrochloride, doxorubicin liposomal, doxycycline, enalaprilat, ephedrine, epinephrine, epirubicin, epotein alfa, eptifibatide, erythromycin, esmolol, etoposide, etoposide phosphate, famotidine, fenoldopam, fentanyl, fluconazole, fludarabine, gemcitabine, gentamicin, glycopyrrolate, granisetron, heparin, hydrocortisone sodium succinate, hydromorphone, idarubicin, ifosfamide, imipenem/cilastatin, insulin, irinotecan, isoproterenol, ketorolac, labetalol, leucovorin calcium, levofloxacin, lidocaine, linezolid, lorazepam, magnesium sulfate, mannitol, mechlorethamine, meperidine, metaraminol, methotrexate, methyldopate, methylprednisolone sodium succinate, metoclopramide, metoprolol, metronidazole, midazolam, milrinone, mitoxantrone, morphine, moxifloxacin, multivitamins, mycophenolate, nalbuphine, naloxone, nesiritide, nitroglycerin, nitroprusside, norepinephrine, octreotide, ondansetron, oxaliplatin, oxytocin, paclitaxel, palonosetron, pamidronate, pancuronium, papaverine, pemetrexed, penicillin G, pentamidine, pentazocine, phentolamine, phenylephrine, phytonadione, potassium acetate, potassium chloride, procainamide, prochlorperazine, promethazine, propranolol, protamine, pyridoxime, quinupristin/dalfopristin, ranitidine, rocuronium, sodium acetate, streptokinase, succinylcholine, sufentanil, tacrolimus, teniposide, theophylline, thiamine, ticarcillin/clavulanate, tirofiban, tobramycin, tolazoline, vancomycin, vasopressin, vecuronium, vinblastine, vincristine, vinorelbine, voriconazole, zoledronic acid
  • Y-Site Incompatibility: acyclovir, albumin, aminophylline, amphotericin B cholesteryl, amphotericin B colloidal, amphotericin B liposome, ampicillin, ampicillin/sulbactam, azathioprine, cefoperazone, ceftazidime, chloramphenicol, dantrolene, diazepam, diazoxide, ertapenem, fluorouracil, folic acid, foscarnet, furosemide, ganciclovir, indomethacin, pantoprazole, pentobarbital, phenobarbital, phenytoin, piperacillin/tazobactam, propofol, sodium bicarbonate, thiotepa, tigecycline, trimethoprim/sulfamethoxazole

Patient/Family Teaching

  • Advise patient to take medication as directed, even if feeling well. Take missed doses as soon as possible unless almost time for next dose; do not double doses. May need to be discontinued gradually.
    • Advise patient to avoid large amounts (6–8 glasses of grapefruit juice/day) during therapy.
    • Instruct patient on correct technique for monitoring pulse. Instruct patient to contact health care professional if heart rate is <50 bpm.
    • Caution patient to change positions slowly to minimize orthostatic hypotension.
    • May cause drowsiness or dizziness. Advise patient to avoid driving or other activities requiring alertness until response to the medication is known.
    • Instruct patient on importance of maintaining good dental hygiene and seeing dentist frequently for teeth cleaning to prevent tenderness, bleeding, and gingival hyperplasia (gum enlargement).
    • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications, especially cold preparations.
    • Advise patient to notify health care professional if irregular heartbeats, rash, dyspnea, swelling of hands and feet, pronounced dizziness, nausea, constipation, or hypotension occurs or if headache is severe or persistent.
    • Caution patient to wear protective clothing and use sunscreen to prevent photosensitivity reactions.
  • Angina: Instruct patient on concurrent nitrate or beta-blocker therapy to continue taking both medications as directed and use SL nitroglycerin as needed for anginal attacks.
    • Advise patient to contact health care professional if chest pain does not improve, worsens after therapy, or occurs with diaphoresis; if shortness of breath occurs; or if severe, persistent headache occurs.
    • Caution patient to discuss exercise restrictions with health care professional before exertion.
  • Hypertension: Encourage patient to comply with other interventions for hypertension (weight reduction, low-sodium diet, smoking cessation, moderation of alcohol consumption, regular exercise, and stress management). Medication controls but does not cure hypertension.
    • Instruct patient and family in proper technique for monitoring BP. Advise patient to take BP weekly and to report significant changes to health care professional.

Evaluation/Desired Outcomes

  • Decrease in BP.
  • Decrease in frequency and severity of anginal attacks.
    • Decrease in need for nitrate therapy.
    • Increase in activity tolerance and sense of well-being.
  • Suppression and prevention of atrial tachyarrhythmias.


A trademark for the drug verapamil.


a trademark for a calcium channel blocker (verapamil hydrochloride).
References in periodicals archive ?
director of the Family Medicine Residency Program at Long Beach Memorial Medical Center in California, who sees the Calan SR Patients-in-Compliance program as a ground-breaking initiative.
Calan Horsman, Phone: +44-207-431-2124, Email: calan@mylifeoftravel.
Our White House was one of a pair available through Meon Villas and facing each other on cliffs at Calan Bruch near Cuidadela.
WASHINGTON -- Two Utah students, Calan Olsen, 17, of Ephraim and Amber Barron, 14, of Riverton, were honored in the nation's capital last night for their outstanding volunteer work during the presentation of The 2010 Prudential Spirit of Community Awards.
Tenders are invited for Supply, Installation and Commissioning of Equipment for the Investment Objective Rehabilitation of the Former Industrial Site Industrial Platform of Calan and Preparation for New Activities.
30 ar greu anifeiliad y nos hefo'r arlunydd Luned Rhys Parri yn barod ar gyfer Calan Gaeaf.
Last year's prize was awarded to Joanna Gruesome for their debut album, Weird Sister the shortlist Calan - Dinas (Sain) | Catfish and the Bottlemen - The Balcony (Island / Communion Records) Geraint Jarman - Dwyn yr Hogyn Nol (AnkstMusic) Gwenno - Y Dydd Olaf (Peski / Heavenly Recordings) H Hawkline - In the Pink Condition (Heavenly Recordings) Hippies vs Ghosts - Droogs Houdini Dax - Naughty Nation (Houdini Dax / Listen to This) Joanna Gruesome - Peanut Butter (Fortuna POP
Cardiff-based Gwenno, Houdini Dax, Keys and Welsh music icon Geraint Jarman will face off against the likes of Hippies vs Ghosts, Calan and Trwbador.
Calan have got pulses racing due to their eye-popping attire banishing traditional folk's image as the sole preserve of Aran-sweater clad blokes with beards.
Mold Rugby Club, August 17-19 VIN Garbutt, Rosie Carson and Kevin Dempsey, Calan, Jez Lowe, Full House and Steve Eaves are among the musicians appearing at this year's Tegeingl folk festival.
Many were taken to hospital after being taken ill at the Hotel Calan Blanes on the Spanish island of Menorca.