Questions and Answers
What is the pharmacologic class of Prazosin?
What are the major actions of Prazosin?
Rapid decrease in peripheral resistance that reduces blood pressure.
The onset of Prazosin is approximately ______ hours.
2
Prazosin has a long half-life.
Signup and view all the answers
What should be administered to avoid severe hypotension when starting Prazosin?
Signup and view all the answers
Prazosin is safe for use during pregnancy.
Signup and view all the answers
Which of the following may be an adverse effect of Prazosin?
Signup and view all the answers
What will Prazosin cause in terms of urine tests?
Signup and view all the answers
What should be avoided when taking Prazosin?
Signup and view all the answers
What can be given to elevate blood pressure in case of overdose?
Signup and view all the answers
Which of the following drugs is NOT in the same class as Prazosin?
Signup and view all the answers
Study Notes
Pharmacologic and Therapeutic Class
- Prazosin belongs to the adrenergic-blocking drug class.
- It is classified therapeutically as an antihypertensive agent.
Actions and Uses
- Acts as a selective alpha1-adrenergic antagonist, blocking norepinephrine at vascular smooth muscle receptors.
- Major benefit includes rapid reduction of peripheral resistance, leading to decreased blood pressure.
- Minimal impact on cardiac output and heart rate compared to other antihypertensives.
- Less reflex tachycardia observed; tolerance may develop over time.
- Commonly prescribed in combination with other drugs like beta blockers or diuretics.
- Short half-life necessitates dosage two to three times daily.
Administration Alerts
- Initiate treatment with a low first dose to prevent severe hypotension.
- Safety during pregnancy (Category C) or while breast-feeding has not been established.
Pharmacokinetics
- Onset of action: approximately 2 hours.
- Peak efficacy occurs between 2 to 4 hours post-administration.
- Effects last for less than 24 hours.
Adverse Effects
- Orthostatic hypotension is a significant risk due to alpha1 receptor blockade.
- Uncommon cases of fainting may occur about 30 minutes after the first dose; hence low initial doses are recommended at bedtime.
- Possible side effects include dizziness, drowsiness, and lightheadedness.
- Rapid blood pressure drop can trigger reflex tachycardia.
- Some patients may experience nasal congestion or ejaculation issues.
Contraindications
- Use is not recommended during pregnancy or lactation without further safety data.
Drug-Drug Interactions
- Combining prazosin with other antihypertensives and diuretics may cause dangerously low blood pressure.
- Alcohol consumption should be avoided while on this medication.
Lab Tests
- Prazosin may lead to increased urinary metabolites of vanillyl-mandelic acid (VMA) and norepinephrine, complicating pheochromocytoma screening tests.
- Can produce false-positive results in lab assessments.
Herbal/Food Interactions
- Avoid products such as saw palmetto or nettle root, as they can block alpha1 receptors resulting in additional hypotensive effects.
Treatment of Overdose
- Hypotension may be the primary outcome of overdose.
- Treatment may involve fluid expanders like normal saline or the use of vasopressors such as dopamine or dobutamine to stabilize blood pressure.
Other Drugs in this Class
- Includes medications such as acebutolol, alfuzosin, atenolol, bisoprolol, and several others with primary action on alpha1 or beta-adrenoceptors.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of Prazosin (miniPress) with these flashcards. Learn about its pharmacologic and therapeutic classes, as well as its actions and uses. Perfect for healthcare students and professionals looking to reinforce their understanding of this antihypertensive medication.
