nifedipine (Procardia, Adalat)
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Introduction
Tradenames: Procardia, Adalat. Verapamil is the preferred agent in this class.
Indications
- hypertrophic cardiomyopathy
- hypertension
- variant (Prinzmetal's angina)
- chronic, stable angina (see ACTION trial)
- Raynaud's phenomenon
- easing passage of urinary calculus[6]
Contraindications
- myocardial ischemia/infarction
- NOT for use in controlling ventricular response to atrial fibrillation -> does NOT block AV nodal conduction
Dosage
Start 10 mg PO TID, max 120 mg/day.
Tabs: 10 & 20 mg.
Sustained release: Procardia XL, Adalat CC.
- Do Not crush, split or chew tablets
- Hypertension: 30-60 mg PO QD, max 120 mg/day.
- Angina: 30 mg QD, max 180 mg/day.
Tabs: 30, 60, 90 mg.
Storage
- store Procardia in its original container
- must be protected from light & moisture
- product labeling for generics does not instruct to dispense in original container
Pharmacokinetics
- 90% of dose is absorbed from GI tract
- extensive 1st pass metabolism
- metabolized in the liver by cyt P450 3A4
- polymorphism of metabolism
- bioavailablity is increased in patients with cirrhosis
- protein binding 92-98%, decreased in patients with renal or hepatic failure
elimination via liver
1/2life = 2-6 hours
protein binding = 96-98 %
elimination by hemodialysis = -
Adverse effects
- common (> 10%)
- less common (1-10%)
- uncommon (< 1%)
- tachycardia, syncope, sweating, fever/chills, dermatitis, urticaria, diarrhea, constipation, gingival hyperplasia, thrombocytopenia, leukopenia, anemia, purpura, arthritis, increased antinuclear antibody (ANA), blurred vision, transient blindness, shortness of breath
- short acting nifedipine
- reflex tachycardia, especially when used with nitrates
- adverse effects in myocardial ischemia/infarction
- negative inotropic effects
- proteinuria: nifedipine dilates both glomerular afferent & efferent arterioles & increases vascular permeability
- nifedipine has anti-platelet effects that may increase bleeding time.
- urinary retention (relaxation of bladder smooth muscle)[8]
- gingival hyperplasia in 20% of elderly[9]
- may appear 1-9 months after initiation of therapy &
- may resolve slowly when nifedipine is discontinued
- photosensitivity
- increased risk of lip cancer[11]
* In contrast to clonidine, nifedipine is well tolerated by most patients. It does not cause Na+ retention.
- drug adverse effects of calcium channel blockers
- drug adverse effects of renin-angiotensin-aldosterone system inhibitors (RAAS inhibitors)
- drug adverse effects of antihypertensive agents
Drug interactions
- beta blockers may increase risk of CHF
- anesthetic doses of fentanyl may cause hypotension
- concurrent administration of cimetidine may increase nifedipine level
- nifedipine may increase serum levels of:
- severe hypotension may occur during surgery in combination with fentanyl
- IV Mg+2 may result in neuromuscular blockade & hypotension
- any drug that inhibits cyt P450 3A4 may increase levels of nifedipine
- grapefruit juice may increase nifedipine levels
- any drug that induces cyt P450 3A4 may diminish levels of nifedipine
- drug interaction(s) of calcium channel blockers with ARBs
- drug interaction(s) of calcium channel blockers with ACE inhibitors
- drug interaction(s) of calcium channel blockers with diuretics
- drug interaction(s) of calcium channel blockers with erythromycin
- drug interaction(s) of calcium channel blockers with clarithromycin
- drug interaction(s) of renin-angiotensin-aldosterone inhibitors with trimethoprim-sulfamethoxazole
- drug interaction(s) of beta-adrenergic receptor antagonists with calcium channel blockers
- drug interaction(s) of NSAIDs & antihypertensives
Laboratory
- specimen: serum, plasma (EDTA)
- methods: GLC, HPLC
- interferences:
- nifedipine may be displaced from protein binding sites by plasticizers in collection devices
Mechanism of action
- L-type Ca+2 channel blocker
- potent arterial & coronary artery dilating properties
- reflex increase in sympathetic tone
- does NOT block AV nodal conduction
Clinical trials
More general terms
Additional terms
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ The Pharmacological Basis of Therapeutics, 8th ed. Gilman et al, eds. Permagon Press/McGraw Hill pg 774
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
- ↑ Kaiser Permanente Northern California Regional Drug Formulary, 1998
- ↑ Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998 Department of Veterans Affairs, VA National Formulary
non formulary drug request - ↑ 6.0 6.1 Clinical Guide to Laboratory Tests, NW Tietz (ed) 3rd ed, WB Saunders, Philadelpha 1995
- ↑ Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=220233&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 8.0 8.1 UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 12-15, 2001
- ↑ 9.0 9.1 Geriatrics Review Syllabus, American Geriatrics Society, 5th edition, 2002-2004
- ↑ Prescriber's Letter 11(9): 2004 Use of Nifedipine or Tamsulosin for Kidney Stones Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=200911&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 11.0 11.1 Friedman GD et al Antihypertensive Drugs and Lip Cancer in Non-Hispanic Whites Archives of Internal Medicine, August 2012 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/22869299 <Internet> http://archinte.jamanetwork.com/article.aspx?articleid=1307567
- ↑ Prescriber's Letter 21(6): 2014 Oral Meds to Keep in Original Containers Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=300622&pb=PRL (subscription needed) http://www.prescribersletter.com