Interactions between Flomax and Heroin
1 drug interaction and 12 additional warnings found for the following 2 drugs:
- Flomax (tamsulosin)
- heroin
Drug interactions
Moderate drug interactions
Moderate:
heroin (Schedule I substance) tamsulosin
Applies to: heroin and Flomax (tamsulosin)
Monitor
Certain psychotherapeutic and other CNS-active agents may have blood pressure-lowering effects and may cause dizziness, orthostatic hypotension, or syncope. These effects may be more likely during treatment initiation, dose escalation, or treatment restart. Coadministration with antihypertensives or other agents with blood pressure-lowering properties, particularly vasodilators and alpha-adrenergic blockers, may result in additive hypotensive or orthostatic effects.
Management
Monitor blood pressure and clinical response during concomitant use, especially when starting or increasing the dose of either agent. Patients should be advised to rise slowly from a sitting or lying position and to report dizziness, lightheadedness, fainting, orthostasis, palpitations, or troublesome changes in pulse or heart rate. Patients should be cautioned that alcohol may enhance blood pressure-lowering effects during concomitant use with antihypertensives or other agents with hypotensive properties. Patients should avoid driving or operating hazardous machinery until they know how the medications affect them.
References (13)
- Sternbach H (1991) "Fluoxetine-associated potentiation of calcium-channel blockers." J Clin Psychopharmacol, 11, p. 390-1
- Shook TL, Kirshenbaum JM, Hundley RF, Shorey JM, Lamas GA (1984) "Ethanol intoxication complicating intravenous nitroglycerin therapy." Ann Intern Med, 101, p. 498-9
- Feder R (1991) "Bradycardia and syncope induced by fluoxetine." J Clin Psychiatry, 52, p. 139
- Ellison JM, Milofsky JE, Ely E (1990) "Fluoxetine-induced bradycardia and syncope in two patients." J Clin Psychiatry, 51, p. 385-6
- Rodriguez de la Torre B, Dreher J, Malevany I, et al. (2001) "Serum levels and cardiovascular effects of tricyclic antidepressants and selective serotonin reuptake inhibitors in depressed patients." Ther Drug Monit, 23, p. 435-40
- Pacher P, Kecskemeti V (2004) "Cardiovascular side effects of new antidepressants and antipsychotics: new drugs, old concerns?" Curr Pharm Des, 10, p. 2463-75
- Andrews C, Pinner G (1998) "Postural hypotension induced by paroxetine." BMJ, 316, p. 595
- (2023) "Product Information. Buprenorphine (buprenorphine)." G.L. Pharma UK Ltd
- (2023) "Product Information. Temgesic (buprenorphine)." Reckitt Benckiser Pty Ltd
- (2026) "Product Information. Urapidil (Carinopharm) (urapidil)." Imported (EU)
- (2020) "Product Information. URAPIDIL ACCORD (urapidil)." ACCORD HEALTHCARE LIMITED
- (2020) "Product Information. Ebrantil (urapidil)." CHEPLAPHARM ARZNEIMITTEL GMBH
- (2026) "Product Information. Urapidil (urapidil)." Imported (Switzerland)
Food/lifestyle interactions
Major food/lifestyle interactions
Major:
heroin (Schedule I substance) Food/Lifestyle
Applies to: heroin
Generally avoid
Alcohol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics including morphine and diamorphine. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.
Generally avoid
Consumption of alcohol while taking some sustained-release formulations of morphine may cause rapid release of the drug, resulting in high systemic levels of morphine that may be potentially lethal. Alcohol apparently can disrupt the release mechanism of some sustained-release formulations. The interaction was observed in in vitro studies using a 24-hour morphine formulation (Avinza 30 mg capsule, available in the U.S. from Ligand Pharmaceuticals). When the capsule was mixed with 900 mL of buffer solutions containing ethanol 20% and 40%, the dose of morphine that was released was alcohol concentration-dependent, leading to a more rapid release of morphine. Although the clinical relevance of this finding is unknown, 'dose-dumping' into the bloodstream is conceivable.
Management
Until more information is available, patients taking sustained-release formulations of morphine should not consume alcohol or use medications that contain alcohol. In general, potent narcotics such as morphine or diamorphine should not be combined with alcohol.
References (6)
- (2024) "Product Information. Morphine Sulfate ER (morphine)." Actavis (formerly Abrika Pharmaceuticals LLP)
- (2025) "Product Information. Actimorph (morphine)." Ethypharm UK Ltd
- (2024) "Product Information. Doloral Sirop (morphine)." Laboratoire Atlas Inc
- (2024) "Product Information. Morphine Sulfate (Medsurge) (morphine)." Medicianz Healthcare Pty Ltd
- (2023) "Product Information. Diacetylmorphine Hydrochloride (diamorphine)." Pharmascience Inc
- Cherrier MM, Shen DD, Shireman L, et al. (2021) "Elevated customary alcohol consumption attenuates opioid effects." Pharmacol Biochem Behav, 4, p. 1-27
Moderate food/lifestyle interactions
Moderate:
tamsulosin Food/Lifestyle
Applies to: Flomax (tamsulosin)
Adjust dosing interval
Food may delay the gastrointestinal absorption of tamsulosin. The time to maximum plasma concentration (Tmax) is reached by 4 to 5 hours under fasted conditions and by 6 to 7 hours when tamsulosin is administered with food. The delay in Tmax has the desirable effect of smoothing the tamsulosin plasma concentration profile, thereby reducing fluctuation of the plasma peak and trough concentrations with multiple dosing. Food may also affect the extent of absorption of tamsulosin. It has been reported that taking tamsulosin under fasted conditions results in a 30% increase in bioavailability (AUC) and 40% to 70% increase in peak plasma concentration (Cmax) compared to fed conditions. The effects of food on the pharmacokinetics of tamsulosin are consistent regardless of whether tamsulosin is taken with a light meal or a high-fat meal.
Management
To ensure uniformity of absorption, tamsulosin should be administered approximately one-half hour following the same meal each day.
References (1)
- (2001) "Product Information. Flomax (tamsulosin)." Boehringer-Ingelheim
Disease interactions
10 potential interactions Applies to: 10 conditions, including Diarrhea, Hypotension, Syncope, Cataract, and Liver Disease.
Autonomic Neuropathy
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Autonomic Neuropathy.
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.
Cataract
Major:
Flomax
The tamsulosin in Flomax has a major potential interaction with Cataract.
Intraoperative Floppy Iris Syndrome (IFIS) has been observed during cataract and glaucoma surgery in some patients on or previously treated with alpha 1 blockers, including tamsulosin. The initiation of therapy with tamsulosin in patients for whom cataract or glaucoma surgery is scheduled is not recommended. The patient's ophthalmologist should be aware if the patient is receiving treatment with this drug and should be prepared for possible modifications to the surgical technique, such as the utilization of iris hooks, iris dilator rings, or viscoelastic substances.
Dehydration
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Dehydration.
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.
Diarrhea
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Diarrhea.
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.
Glaucoma/Intraocular Hypertension
Major:
Flomax
The tamsulosin in Flomax has a major potential interaction with Glaucoma/Intraocular Hypertension.
Intraoperative Floppy Iris Syndrome (IFIS) has been observed during cataract and glaucoma surgery in some patients on or previously treated with alpha 1 blockers, including tamsulosin. The initiation of therapy with tamsulosin in patients for whom cataract or glaucoma surgery is scheduled is not recommended. The patient's ophthalmologist should be aware if the patient is receiving treatment with this drug and should be prepared for possible modifications to the surgical technique, such as the utilization of iris hooks, iris dilator rings, or viscoelastic substances.
Hypotension
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Hypotension.
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.
Liver Disease
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Liver Disease.
Patients with moderate hepatic impairment do not require any adjustment in tamsulosin dosage. Tamsulosin has not been studied in patients with severe hepatic impairment.
Renal Dysfunction
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Renal Dysfunction.
Patients with renal impairment do not require an adjustment in tamsulosin dosing. However, patients with end-stage renal disease (Clcr <10 mL/min) have not been studied.
Syncope
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Syncope.
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.
Vomiting
Moderate:
Flomax
The tamsulosin in Flomax has a moderate potential interaction with Vomiting.
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.
More resources
Flomax
A total of 344 drugs are known to interact with Flomax.
- Flomax is in the drug class alpha blockers.
- Flomax is used to treat Benign Prostatic Hyperplasia.
heroin
A total of 407 drugs are known to interact with heroin.
- Heroin is in the drug class illicit (street) drugs.
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.