We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Article |

Histamine2-Receptor Antagonists and Cardiovascular Drugs

David Hasdai, MD
Arch Intern Med. 1991;151(4):814-815. doi:10.1001/archinte.1991.00400040142036.
Text Size: A A A
Published online


To the Editor.—  In the April 1990 issue of the Archives, Lipsy et al1 reviewed the various histamine2 receptor antagonists. I would like to comment on the section describing the drug interactions of histamine2 antagonists and cardiovascular drugs.The authors state that the clearance of propranolol is decreased by both cimetidine and ranitidine, thus causing increased levels of propranolol in the blood. However, whereas cimetidine increases propranolol concentrations in the blood and potentiates β-blocking effects through inhibition of hepatic microsomal enzymes and reduction of hepatic blood flow,2 ranitidine has no effect on propranolol metabolism or clearance.2The authors failed to address the interaction between histamine2 receptor antagonists and the calcium-channel blockers that are becoming increasingly popular. Increased blood levels of diltiazem are detected when this drug is administered concurrently with ranitidine and, more so, with cimetidine.3 Cimetidine causes increased levels of nifedipine, which might


Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview





Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.