verapamil

[vera- (shortening and alteration of VALERIC ACID) + -pamil, vasodilating drug suff. (perhaps P(ROPYL) + AM(INO) + (NITR)IL(E)).]

Brand names: Calan®Calan® SRCovera-HS®Isoptin®Isoptin® SRVerelan®Verelan® PM

Chemical formula:

Drug Forms:
• Verapamil Hydrochloride Oral tablet (below)
• Verapamil Hydrochloride Oral capsule, extended-release
• Verapamil Hydrochloride Oral tablet, extended-release
• Verapamil injection
• Verapamil Hydrochloride Modified-release tablet
• Verapamil Hydrochloride Oral capsule, modified-release
• Verapamil Hydrochloride Solution for injection

Español:
• Clorhidrato de verapamilo, Tableta oral
• Clorhidrato de verapamilo, Cápsula oral de liberación prolongada
• Verapamilo Clorhidrato, Tableta oral de liberación prolongada
• Inyección de verapamilo
• Clorhidrato de verapamilo, Tableta de liberación modificada
• Clorhidrato de verapamilo, Cápsula oral de liberación modificada
• Clorhidrato de verapamilo, Solución para inyección

Verapamil Hydrochloride Oral tablet

What is this medicine?

VERAPAMIL is a calcium-channel blocker. It affects the amount of calcium found in your heart and muscle cells. This relaxes your blood vessels, which can reduce the amount of work the heart has to do. This medicine is used to treat chest pain caused by angina, high blood pressure, and controls heart rate in certain conditions.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
•heart or blood vessel disease
•heart rhythm disturbances such as sick sinus syndrome, ventricular arrhythmias, Wolff-Parkinson-White syndrome, or Lown-Ganong-Levine syndrome
•liver or kidney disease
•low blood pressure
•an unusual or allergic reaction to verapamil, other medicines, foods, dyes, or preservatives
•pregnant or trying to get pregnant
•breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. This medicine can be taken with or without food. Take your doses at regular intervals. Do not take your medicine more often than directed.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What may interact with this medicine?

Do not take this medicine with any of the following:
•cisapride
•disopyramide
•dofetilide
•grapefruit juice
•hawthorn
•pimozide
•red yeast rice

This medicine may also interact with the following medications:
•barbiturates such as phenobarbital
•cimetidine
•cyclosporine
•lithium
•local anesthetics or general anesthetics
•medicines for heart rhythm problems like amiodarone, digoxin, flecainide, procainamide, quinidine
•medicines for high blood pressure or heart problems
•medicines for seizures like carbamazepine and phenytoin
•rifampin, rifabutin or rifapentine
•theophylline or aminophylline

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Check your blood pressure and pulse rate regularly. Ask your doctor or health care professional what your blood pressure and pulse rate should be and when you should contact him or her. Do not suddenly stop taking this medicine. Ask your doctor or health care professional how to gradually reduce the dose.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
•difficulty breathing
•dizziness or light headedness
•fainting
•fast heartbeat, palpitations, irregular heartbeat, or chest pain
•skin rash
•slow heartbeat
•swelling of the legs or ankles

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
•constipation
•facial flushing
•headache
•nausea, vomiting
•sexual dysfunction
•weakness or tiredness

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15 and 25 degrees C (59 and 77 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.

Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.

A calcium channel blocking agent used as a vasodilator and in the treatment of cardiac arrhythmias.

The noun has one meaning:

Meaning #1: a drug (trade names Calan and Isoptin) used as an oral or parenteral calcium blocker in cases of hypertension or congestive heart failure or angina or migraine
  Synonyms: Calan, Isoptin

Verapamil
Systematic (IUPAC) name
(RS)-2-(3,4-dimethoxyphenyl)-5-[[2-(3,4-dimethoxyphenyl)ethyl]- (methyl)amino]-2-isopropylpentanenitrile
Identifiers
CAS number	52-53-9
ATC code	C08DA01
PubChem	2520
DrugBank	APRD00335
ChemSpider	2425
Chemical data
Formula	C27H38N2O4
Mol. mass	454.602 g/mol
SMILES	eMolecules & PubChem
Pharmacokinetic data
Bioavailability	35.1%
Metabolism	Hepatic
Half life	2.8-7.4 hours
Excretion	Renal: 11%
Therapeutic considerations
Pregnancy cat.	C(US)
Legal status	℞ Prescription only
Routes	Oral, Intravenous
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Verapamil (brand names: Isoptin, Verelan, Verelan PM, Calan, Bosoptin, Covera-HS) is an L-type calcium channel blocker of the phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches.^[1] It is also an effective preventive medication for migraine. Verapamil has also been used as a vasodilator during cryopreservation of blood vessels. It is a class 4 antiarrhythmic, more effective than digoxin in controlling ventricular rate, and was approved by the United States Food and Drug Administration in 1981.

Contents 1 Mechanism and uses 2 Pharmacokinetic details 3 Side effects 4 Uses in cell biology 5 Veterinary use 6 Potential Use in the Treatment of Malaria 7 References 8 External links

Mechanism and uses

Verapamil's mechanism in all cases is to block voltage-dependent calcium channels.

In cardiac pharmacology, calcium channel blockers are considered class IV antiarrhythmic agents. Since calcium channels are especially concentrated in the sinoatrial and atrio-ventricular nodes, these agents can be used to decrease impulse conduction through the AV node, thus protecting the ventricles from atrial tachyarrhythmias.

Calcium channels are also present in the smooth muscle that lines blood vessels. By relaxing the tone of this smooth muscle, calcium-channel blockers dilate the blood vessels. This has led to their use in treating hypertension and angina pectoris.

The pain of angina is caused by a deficit in oxygen supply to the heart. Calcium channel blockers like Verapamil will dilate blood vessels, which increases the supply of blood and oxygen to the heart. This controls chest pain, but only when used regularly. It does not stop chest pain once it starts. A more powerful vasodilator such as nitroglycerin may be needed to control pain once it starts.

Pharmacokinetic details

Given orally, 90–100% of Verapamil is absorbed, but due to high first-pass metabolism, bioavailability is much lower (10–35%). It is 90% bound to plasma proteins and has a volume of distribution of 3–5 L/kg⁻¹. It is metabolized in the liver to at least 12 inactive metabolites (though one metabolite, norverapamil, retains 20% of the vasodilating activity of the parent drug). As its metabolites, 70% is excreted in the urine and 16% in feces; 3–4% is excreted unchanged in urine. This is a non-linear dependence between plasma concentration and dosage. Onset of action is 1–2 hours after oral dosage. Half-life is 5–12 hours (with chronic dosages). It is not cleared by hemodialysis.

Verapamil has been reported to be effective in both short-term^[2] and long-term treatment of mania and hypomania.^[3] Addition of magnesium oxide to the verapamil treatment protocol enhances the antimanic effect.^[4] It has on occasion been used to control mania in pregnant patients, especially in the first 3 months. It does not appear to be significantly teratogenic. For this reason, when one wants to avoid taking valproic acid (which is high in teratogenicity) or lithium (which has a small but significant incidence of causing cardiac malformation), Verapamil is usable as an alternative, albeit presumably a less effective one.

Side effects

Some possible side effects of the drug are headaches, facial flushing, dizziness, swelling, increased urination, fatigue, nausea, ecchymosis, lightheadedness, and constipation.

Uses in cell biology

Verapamil is also used in cell biology as an inhibitor of drug efflux pump proteins such as P-glycoprotein.^[5] This is useful as many tumor cell lines overexpress drug efflux pumps, limiting the effectiveness of cytotoxic drugs or fluorescent tags. It's also used in fluorescent cell sorting for DNA content, as it blocks efflux of a variety of DNA-binding fluorochromes such as Hoechst 33342.

Veterinary use

Intra-abdominal adhesions are common in rabbits following surgery. Verapamil can be given post-operatively in rabbits who have suffered trauma to abdominal organs to prevent formation of these intra-abdominal adhesions.

Potential Use in the Treatment of Malaria

Recent resistance to the anti-malarial drug chloroquine has hindered the treatment of malaria in Southeast Asia, South America and Africa. Resistance to chloroquine is caused by the parasite cell's ability to expel the drug outside of its digestive vacuole. It has been shown that verapamil, when used in combination with chloroquine, enhances the accumulation of chloroquine within a parasitic cell's digestive vacuole, rendering it incapable of detoxifying itself and making it more susceptible to death.^[6][7]

References

1. ^ Ellen Beck; William J. Sieber; Raul Trejo (2005). "Management of Cluster Headaches". American Family Physician 71 (4): 717–724. http://www.aafp.org/afp/20050215/717.html. 
2. ^ AJ Giannini, J Houser, MC Giannini, RH Loiselle (01 Dec 1984). "Antimanic effects of verapamil". American Journal of Psychiatry 141 (12): 1602–1605. PMID 6439057. http://ajp.psychiatryonline.org/cgi/content/abstract/141/12/1602. 
3. ^ AJ Giannini, RS Taraszewski, RH Loiselle (01 Dec 1987). "Verapamil and lithium in maintenance therapy of manic patients". Journal of Clinical Pharmacology 27 (12): 980–986. PMID 3325531. http://jcp.sagepub.com/cgi/content/abstract/27/12/980. 
4. ^ AJ Giannini, AM Nakoneczie, SM Melemis, J Ventresco, M Condon (2000). "Magnesium oxide augmentation of verapamil maintenance therapy in mania". Psychiatry Research 93: 83–87. doi:10.1016/S0165-1781(99)00116-X. 
5. ^ Bellamy WT. (1996). "P-glycoproteins and multidrug resistance". Annu Rev Pharmacol Toxicol 36: 161–83. doi:10.1146/annurev.pa.36.040196.001113. PMID 8725386. 
6. ^ Martin, S. K., A. M. Oduola, and W. K. Milhous (1987). "Reversal of chloroquine resistance in Plasmodium falciparum by verapamil". Science 235: 899–901. doi:10.1126/science.3544220. PMID 3544220. 
7. ^ Krogstad, D.J., et al (1987). "Efflux of Chloroquine from Plasmodium falciparum: Mechanism of Chloroquine Resistance". Science 238: 1283. doi:10.1126/science.3317830. http://sciencemag.org/cgi/search?volume=238&firstpage=1283&search_citation-search.x=44&search_citation-search.y=2&search_citation-search=search. 

External links

• MedlinePlus DrugInfo medmaster-a684030
• Securon Summary of Product Characteristics

v • d • e Antiarrhythmic agents (C01B) Channel blockers class I (Na+ channel blockers) class Ia (Phase 0→ and Phase 3→) Procainamide # • Quinidine # • Ajmaline • Disopyramide • Prajmaline • Sparteine class Ib (Phase 3←) IV (Lidocaine #) • enteral (Mexiletine, Tocainide, Aprindine) class Ic (Phase 0→) Encainide • Flecainide • Lorcainide • Moricizine • Propafenone class III (Phase 3→, K+ channel blockers) Amiodarone • Bretylium • Bunaftine • Dofetilide • Ibutilide • Nifekalant • Sotalol • Tedisamil • E-4031 class IV (Phase 4→, Ca2+ channel blockers) Verapamil # • Diltiazem Receptor agonists and antagonists class II (Phase 4→, β blockers) Propranolol • Nadolol • Pindolol • cardioselective (Atenolol, Metoprolol, Acebutolol, Esmolol) A1 agonist Adenosine M2 muscarinic antagonist: Atropine • Quinidine • Disopyramide muscarinic agonist: Digoxin α receptors Quinidine • Verapamil • Amiodarone • Bretylium Ion transporters Na+ / K+-ATPase Digoxin # = WHO-EM

v • d • e Channel blocker: calcium channel blockers (C08) Selective Dihydropyridines ("-dipine") Amlodipine# • Aranidipine • Azelnidipine • Barnidipine • Benidipine • Cilnidipine • Clevidipine • Efonidipine • Felodipine • Isradipine • Lacidipine • Manidipine • Lercanidipine • Nicardipine • Nifedipine# • Nilvadipine • Nimodipine • Nisoldipine • Nitrendipine • Pranidipine Phenylalkylamines ("-pamil") Gallopamil • Verapamil 1-4 Benzothiazepines ("-tiazem") Diltiazem • Clentiazem Non-selective Fendiline • Bepridil • Lidoflazine • Perhexiline Other/ungrouped Amrinone  • Anandamide  • Anipamil  • Azimilide  • Bencyclane  • Bepridil  • Berbamine  • Bevantolol  • Canadine  • Carboxyamido-Triazole  • Caroverine  • Cinnarizine  • Conotoxins  • Darodipine  • Dauricine  • Devapamil  • Dimeditiapramine  • Dotarizine  • Emopamil  • Enpiperate  • Eperisone  • Falipamil  • Fantofarone  • Fasudil  • Fenamic acid  • Fendiline  • Flunarizine  • Fosfedil  • Gabapentin  • Lamotrigine  • Lidoflazine  • Magnesium sulfate  • Manoalide  • Mepirodipine  • Mibefradil  • Monatepil  • Naftopidil  • Niguldipine  • Niludipin  • Norverapamil  • Ochratoxin A  • Octylonium  • Osthol  • Oxodipine  • Perhexiline  • Pinaverium  • Piperidine  • Pregabalin  • Prenylamine  • Risedronic acid  • Ryodipine  • Sesamodil  • Stepholidine  • Terodiline  • Tetrahydropalmatine  • Tetrandrine  • Tolfenamic acid  • Tranilast #WHO-EM. ‡Withdrawn from market. CLINICAL TRIALS: †Phase III. §Never to phase III

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