Prazosin Hydrochloride interactions

Food & lifestyle

• alcohol

  Moderate

  Synergy

  The concurrent use of ethanol and alpha-1 adrenergic blockers may cause increased hypotensive effects. Patients with aldehyde dehydrogenase deficiencies (primarily Asians) may be at a higher risk of this interaction.

  What to do: Patients who develop a flushing reaction after ethanol ingestion (indicates a possible aldehyde dehydrogenase deficiency) should be advised to avoid ethanol or limit their intake. All patients should be warned about the possibility of orthostatic hypotension with concurrent ethanol use.

  2 sources

  1. Kawano Y, Abe H, Kojima S, Takishita S, Omae T "Interaction of alcohol and an a1-blocker on ambulatory blood pressure in patients with essential hypertension." Am J Hypertens 13 (2000): 307-12
  2. "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc (2002):

Conditions

Conditions in which Prazosin Hydrochloride needs care, as documented in this source.

• Hypotension

  Moderate

  Peripheral alpha 1- adrenergic receptor blocking agents (aka alpha 1- blockers) cause vasodilation and can produce marked hypotension, especially orthostatic hypotension with syncope or other postural symptoms such as dizziness, lightheadedness, and palpitations. Orthostatic effects are most common during initiation of therapy and often occur within 90 minutes after the first dose. However, they can also occur following a dosage increase or resumption of therapy after an interruption of more than a few days. Agents with alpha 1a specificity, such as tamsulosin, act primarily on the prostate but are not devoid of hypotensive effects. Therapy with peripheral alpha-1 blockers should be administered cautiously in patients with or predisposed to hypotensive or syncopal episodes. Caution is also advised in patients who are dehydrated (e.g., due to severe or prolonged diarrhea or vomiting), since they may be more sensitive to the hypotensive effect of the drugs. Therapy should be initiated with the lowest dosage possible and titrated gradually based on patient response and tolerance in accordance with the individual product package labeling. During initiation or reinstitution of therapy and following an increase in dosage, patients should be advised not to rise abruptly from a sitting or recumbent position and to avoid situations where injury could result if syncope occur. Concomitant use of alcohol, extensive periods of standing, prolonged or intense exercise, and exposure to heat can also precipitate orthostatic hypotension and should be minimized. If dizziness, lightheadedness or palpitations occur, the patient should sit or lie down, and seek medical attention if symptoms are recurrent or bothersome.

  16 sources

  1. Grunstein JA "The problem of postural hypotension." Gerontol Clin (Basel) 16 (1974): 171-4
  2. Glass AR, Ballou R "Pheochromocytoma, prazosin, and hypotension." Ann Intern Med 97 (1982): 455
  3. Melkild A "Prazosin (peripress): a long-term study." Curr Med Res Opin 9 (1984): 219-28
  4. Graham RM, Thornell IR, Gain JM, Bagnoli C, Oates HF, Stokes GS "Prazosin: the first-dose phenomenon." Br Med J 2 (1976): 1293-4
  5. "Prazosin (Minipress) for hypertension." Med Lett Drugs Ther 19 (1977): 1-2
  6. Salim SS, Mtui EP, Makene WJ "An open evaluation of the efficacy and toleration of prazosin in patients with hypertension." East Afr Med J 54 (1977): 429-33
  7. "Product Information. Cardura (doxazosin)." Pfizer U.S. Pharmaceuticals (2001):
  8. "Product Information. Hytrin (terazosin)." Abbott Pharmaceutical (2001):

  Show all 16 sourcesShow fewer sources

  9. Troffa C, Manunta P, Dessifulgheri P, Pazzola A, Sabino G, Patteri G, Tonolo G, Pupita G, Glorioso N, Gitti M, Rappelli A "Efficacy and tolerability of doxazosin alone or in combination with chlorthalidone in essential hypertension." Curr Ther Res Clin Exp 55 (1994): 22-31
  10. Ahaneku JE, Taylor OG, Walker D, Agbedana OE, Salako LA "Blood pressure and biochemical changes during doxazosin monotherapy in nigerian hypertensive patients." Curr Ther Res Clin Exp 55 (1994): 1067-74
  11. Takata Y, Yoshizumi T, Ito Y, Hirota Y, Fujishima M "Effect of administration and withdrawal of doxazosin on ambulatory blood pressure in patients with essential hypertension." Angiology 46 (1995): 11-8
  12. Limbird LE eds., Gilman AG, Hardman JG "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: McGraw-Hill (1995):
  13. Roehrborn CG, Siegel RL "Safety and efficacy of doxazosin in benign prostatic hyperplasia: a pooled analysis of three double-blind, placebo-controlled studies." Urology 48 (1996): 406-15
  14. "Product Information. Flomax (tamsulosin)." Boehringer-Ingelheim (2001):
  15. "Product Information. Uroxatral (alfuzosin)." sanofi-aventis (2003):
  16. "Product Information. Rapaflo (silodosin)." Watson Pharmaceuticals (2008):

• Liver Diseases

  Moderate

  Little data exist concerning the pharmacokinetic disposition of prazosin in patients with liver disease. Prazosin is known to be metabolized by the liver and subsequently excreted in the bile, primarily as metabolites. Some of the metabolites are pharmacologically active and possess 10% to 25% of the hypotensive activity of prazosin. Therapy with prazosin should be administered cautiously in patients with significantly impaired hepatic or biliary function, since drug and/or metabolite accumulation may occur.

  1 source

  1. Bateman DN, Rawlins MD "Prazosin concentration-effect, metabolism and biological activity of metabolites." Br J Clin Pharmacol 11 (1981): 221-

Therapeutic duplication

Drug classes that overlap with Prazosin Hydrochloride, so taking both doubles up the same effect. This source publishes no per-row citations for duplication.

• peripherally acting antihyperten

  The recommended maximum number of medicines in the 'peripherally acting antihypertensives' category to be taken concurrently is usually one.Your list includes two medicines belonging to the 'peripherally acting antihypertensives' category.

  Example product in the source data (US market): Hydralazine/isosorbide dinitrate

• peripherally acting antihyperten

  The recommended maximum number of medicines in the 'peripherally acting antihypertensives' category to be taken concurrently is usually one.Your list includes two medicines belonging to the 'peripherally acting antihypertensives' category.

  Example product in the source data (US market): Hydralazine/hydrochlorothiazide/reserpine

• peripherally acting antihyperten

  The recommended maximum number of medicines in the 'peripherally acting antihypertensives' category to be taken concurrently is usually one.Your list includes two medicines belonging to the 'peripherally acting antihypertensives' category.

  Example product in the source data (US market): Hydralazine/hydrochlorothiazide