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Drug overview for DIBENZYLINE (phenoxybenzamine hcl):
Generic name: PHENOXYBENZAMINE HCL (fen-OX-ee-BEN-za-meen)
Drug class: Alpha-Blockers
Therapeutic class: Cardiovascular Therapy Agents
Phenoxybenzamine hydrochloride is a haloalkylamine alpha-adrenergic blocking agent.
No enhanced Uses information available for this drug.
Generic name: PHENOXYBENZAMINE HCL (fen-OX-ee-BEN-za-meen)
Drug class: Alpha-Blockers
Therapeutic class: Cardiovascular Therapy Agents
Phenoxybenzamine hydrochloride is a haloalkylamine alpha-adrenergic blocking agent.
No enhanced Uses information available for this drug.
DRUG IMAGES
DIBENZYLINE 10 MG CAPSULE
The following indications for DIBENZYLINE (phenoxybenzamine hcl) have been approved by the FDA:
Indications:
Pheochromocytoma adjunct therapy
Professional Synonyms:
Adjunct medication therapy for pheochromocytoma
Indications:
Pheochromocytoma adjunct therapy
Professional Synonyms:
Adjunct medication therapy for pheochromocytoma
The following dosing information is available for DIBENZYLINE (phenoxybenzamine hcl):
No enhanced Dosing information available for this drug.
Phenoxybenzamine hydrochloride is administered orally. GI irritation may be reduced by giving the drug with milk or in divided doses.
| DRUG LABEL | DOSING TYPE | DOSING INSTRUCTIONS |
|---|---|---|
| DIBENZYLINE 10 MG CAPSULE | Maintenance | Adults take 1 capsule (10 mg) by oral route 2 times per day |
| DRUG LABEL | DOSING TYPE | DOSING INSTRUCTIONS |
|---|---|---|
| PHENOXYBENZAMINE HCL 10 MG CAP | Maintenance | Adults take 1 capsule (10 mg) by oral route 2 times per day |
The following drug interaction information is available for DIBENZYLINE (phenoxybenzamine hcl):
There are 0 contraindications.
There are 0 severe interactions.
There are 3 moderate interactions.
The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.
| Drug Interaction | Drug Names |
|---|---|
| CGMP Specific PDE Type-5 Inhibitors/Alpha-Blockers SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of avanafil,(1) sildenafil,(2-5) tadalafil,(6-9) or vardenafil(10-14) and an alpha-blocker may result in additive or synergistic effects on blood pressure. CLINICAL EFFECTS: Concurrent use of avanafil,(1) sildenafil,(2-5) tadalafil,(6-9) or vardenafil(10-14)) and an alpha-blocker may result in symptomatic hypotension. PREDISPOSING FACTORS: Patients who have a history of hemodynamic instability on alpha-blocker therapy prior to initiating avanafil, sildenafil, tadalafil, or vardenafil may be at an increased risk of symptomatic hypotension during concurrent therapy. PATIENT MANAGEMENT: The US manufacturer of avanafil states that patients taking alpha-blockers should be stabilized on their alpha-blocker prior to beginning avanafil therapy. Avanafil should be initiated at the 50 mg dosage. In patients stabilized on avanafil therapy, alpha-blocker therapy should be initiated at the lowest possible dosage.(1) The US, Australian, Canadian, and UK manufacturers of sildenafil state that patients taking alpha-blockers should be stabilized on their alpha-blocker prior to beginning sildenafil therapy. Sildenafil should be initiated at the lowest possible dosage. In patients stabilized on sildenafil therapy, alpha-blocker therapy should be initiated at the lowest possible dosage.(2-5) The US manufacturer of tadalafil states that patients taking tadalafil for erectile dysfunction (ED) and alpha-blockers should be stabilized on their alpha-blocker prior to beginning tadalafil therapy. Tadalafil should be initiated at the lowest possible dosage. In patients stabilized on tadalafil therapy, alpha-blocker therapy should be initiated at the lowest possible dose. The combination of tadalafil and an alpha-blocker for treatment of benign prostatic hyperplasia (BPH) is not recommended. Patients on alpha-blocker therapy for BPH should discontinue their alpha-blocker at least one day prior to starting tadalafil for once daily use for the treatment of BPH.(6) The Australian manufacturer of tadalafil states that tadalafil should be used with caution in patients taking alpha-blockers.(7) The Canadian manufacturer of tadalafil states that it may be used with tamsulosin and should be used with caution with other alpha-blockers.(8) The UK manufacturer of tadalafil states that concurrent use with alpha-blockers is not recommended.(9) The US, Canadian, and UK manufacturers of vardenafil state that patients taking alpha-blockers should be stabilized on their alpha-blocker prior to beginning vardenafil therapy. Vardenafil should be initiated at the lowest possible dosage. In patients stabilized on vardenafil therapy, alpha-blocker therapy should be initiated at the lowest possible dosage.(10-12) The UK manufacturer of vardenafil states that vardenafil may be give at any time in relation to tamsulosin; however, a dose separation period of 6 hour should be considered for other alpha-blockers.(12) The Australian manufacturer of vardenafil states that concurrent use with alpha-blockers is not recommended.(13) The US manufacturers of doxazosin,(14) prazosin(15) and terazosin(16) state that PDE-5 inhibitor therapy should be initiated at the lowest dose. DISCUSSION: In a study in 24 subjects, concurrent use of avanafil (200 mg) with doxazosin (1 mg on Day 1, titrated to 8 mg for Days 8-18) resulted in 7 subjects experiencing potentially clinically significant changes in blood pressure.(1) In a study in 24 subjects, concurrent use of avanafil (200 mg) with tamsulosin (0.4 mg Days 1-11) resulted in 5 subjects experiencing potentially clinically significant changes in blood pressure.(1) Simultaneous administration of sildenafil (25 mg) and doxazosin (4 mg) resulted in mean additional reductions of supine blood pressure of 7 mmHg systolic and 7 mmHg diastolic. When doxazosin (4 mg) was simultaneously administered with higher doses of sildenafil, there were reports of symptomatic postural hypotension within one to four hours.(2) In a study, concurrent administration of a single dose of tadalafil (20 mg) to healthy subjects receiving alfuzosin (10 mg daily) resulted in mean maximum decreases in standing and supine systolic blood pressure by 2.2 mmHg and 4.4 mmHg, respectively. There were no subjects with a decrease from baseline standing systolic blood pressure greater than 30 mmHg.(6) In a study, concurrent administration of a single dose of tadalafil (20 mg) to 18 healthy subjects receiving doxazosin (8 mg daily) resulted in significant augmentation of the blood-pressure lowering effects of doxazosin (by 9.8 mmHg). The number of subjects with a standing blood pressure of less than 85 mmHg was greater after concurrent doxazosin and tadalafil than when compared to doxazosin with placebo (28% versus 6%). One subject reported vertigo and another reported dizziness. No syncope was reported.(5,14) In a second study, concurrent administration of a single dose of tadalafil (20 mg) to healthy subjects receiving doxazosin (4-8 mg daily) also resulted in augmentation of the blood-pressure lowering affects of doxazosin. One subject reported symptomatic hypotension and another reported dizziness with concurrent therapy.(6) In a study, concurrent administration of a single dose of tadalafil (20 mg) to healthy subjects receiving tamsulosin (0.4 mg daily) resulted in no significant decreases in blood pressure.(6,17) Hypotension has been reported with concurrent use of terazosin and phosphodiesterase-5 inhibitors.(16) With simultaneous administration of vardenafil (10 mg) and terazosin (10 mg), 6 of 8 healthy subjects experienced a standing systolic blood pressure of less than 85 mmHg. With simultaneous vardenafil (20 mg) and terazosin (10 mg), 2 of 9 subjects experienced a standing systolic blood pressure of less than 85 mmHg. When vardenafil (20 mg) was administered 6 hours apart from terazosin (10 mg), 7 of 28 subjects experienced a standing systolic blood pressure of less than 85 mmHg.(10) With simultaneous administration of vardenafil (10 mg) and tamsulosin (0.4 mg), two of 16 subjects experienced a standing systolic blood pressure of less than 85 mmHg. When vardenafil (20 mg) was administered six hours apart from tamsulosin (0.4 mg), one of 24 subjects experienced a standing systolic blood pressure of less than 85 mmHg.(10) In a study in subjects with benign prostatic hyperplasia (BPH) on stable tamsulosin or terazosin therapy, simultaneous vardenafil (5 mg) and tamsulosin resulted in no effects on blood pressure. Simultaneous vardenafil (5 mg) with terazosin resulted in hypotension in some subjects. This effect did not occur when vardenafil and terazosin were separated by 6 hours.(12) In a placebo controlled, crossover study in 22 subjects with benign prostatic hyperplasia receiving tamsulosin, subjects received single doses of vardenafil (10 mg and 20 mg). No patients exhibited symptomatic hypotension. Three patients receiving 20 mg of vardenafil reported dizziness, but none had a systolic blood pressure of less than 95 mmHg.(18) In a placebo-controlled study in 24 health male subjects, administration of sildenafil (100 mg) or tadalafil (20 mg) with silodosin resulted in an increase in positive orthostatic tests in the 12 hours after concurrent administration when compared with the administration of silodosin alone. There were no reports of symptomatic orthostasis or dizziness.(19) |
ADCIRCA, ALYQ, AVANAFIL, CIALIS, ENTADFI, OPSYNVI, REVATIO, SILDENAFIL CITRATE, STENDRA, TADALAFIL, TADLIQ, VARDENAFIL HCL, VIAGRA |
| Tizanidine/Selected Antihypertensives SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Tizanidine is an alpha-2 agonist. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1) CLINICAL EFFECTS: Concurrent use of antihypertensives and tizanidine may result in hypotension.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. The risk of hypotension may be decreased by careful titration of tizanidine dosages and monitoring for hypotension prior to dose advancement. Counsel patients about the risk of orthostatic hypotension.(1) DISCUSSION: Severe hypotension has been reported following the addition of tizanidine to existing lisinopril therapy.(2-4) |
TIZANIDINE HCL, ZANAFLEX |
| Apomorphine/Selected Antihypertensives and Vasodilators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Apomorphine causes dose-dependent decreases in blood pressure. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1) CLINICAL EFFECTS: Concurrent use of antihypertensives and apomorphine may result in orthostatic hypotension with or without dizziness, nausea, or syncope.(1) PREDISPOSING FACTORS: The risk of orthostatic hypotension may be increased during dose escalation of apomorphine and in patients with renal or hepatic impairment.(1) PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. Counsel patients about the risk of orthostatic hypotension.(1) DISCUSSION: Healthy volunteers who took sublingual nitroglycerin (0.4 mg) concomitantly with apomorphine experienced a mean largest decrease in supine systolic blood pressure (SBP) of 9.7 mm Hg and in supine diastolic blood pressure (DBP) of 9.3 mm Hg, and a mean largest decrease in standing SBP and DBP of 14.3 mm Hg and 13.5 mm Hg, respectively. The maximum decrease in SBP and DBP was 65 mm Hg and 43 mm Hg, respectively. When apomorphine was taken alone, the mean largest decrease in supine SBP and DBP was 6.1 mm Hg and 7.3 mm Hg, respectively, and in standing SBP and DBP was 6.7 mm Hg and 8.4 mm Hg, respectively.(1) |
APOKYN, APOMORPHINE HCL, ONAPGO |
The following contraindication information is available for DIBENZYLINE (phenoxybenzamine hcl):
Drug contraindication overview.
No enhanced Contraindications information available for this drug.
No enhanced Contraindications information available for this drug.
There are 1 contraindications.
Absolute contraindication.
| Contraindication List |
|---|
| Severe hypotension |
There are 0 severe contraindications.
There are 3 moderate contraindications.
Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.
| Moderate List |
|---|
| Coronary artery disease |
| Kidney disease with reduction in glomerular filtration rate (GFr) |
| Lower respiratory infection |
The following adverse reaction information is available for DIBENZYLINE (phenoxybenzamine hcl):
Adverse reaction overview.
No enhanced Common Adverse Effects information available for this drug.
No enhanced Common Adverse Effects information available for this drug.
There are 0 severe adverse reactions.
There are 11 less severe adverse reactions.
| More Frequent | Less Frequent |
|---|---|
|
Miosis Nasal congestion Orthostatic hypotension Tachycardia |
Acute cognitive impairment Disorder of ejaculation Drowsy Fatigue Headache disorder Xerostomia |
| Rare/Very Rare |
|---|
|
Accidental fall |
The following precautions are available for DIBENZYLINE (phenoxybenzamine hcl):
No enhanced Pediatric Use information available for this drug.
Contraindicated
Severe Precaution
Management or Monitoring Precaution
Contraindicated
| None |
Severe Precaution
| None |
Management or Monitoring Precaution
| None |
Animal reproduction studies have not been performed with phenoxybenzamine, and it is not known whether the drug can cause fetal harm when administered to pregnant women. The drug has been used in a limited number of women during the third trimester of pregnancy in the treatment of hypertension caused by pheochromocytoma without apparent harm to the woman or fetus. Phenoxybenzamine should be used during pregnancy only when clearly needed.
It is not known whether phenoxybenzamine is distributed in human milk. Because of the potential for serious adverse reactions to phenoxybenzamine in nursing infants, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.
No enhanced Geriatric Use information available for this drug.
The following prioritized warning is available for DIBENZYLINE (phenoxybenzamine hcl):
No warning message for this drug.
No warning message for this drug.
The following icd codes are available for DIBENZYLINE (phenoxybenzamine hcl)'s list of indications:
| Pheochromocytoma adjunct therapy | |
| C74.1 | Malignant neoplasm of medulla of adrenal gland |
| C74.10 | Malignant neoplasm of medulla of unspecified adrenal gland |
| C74.11 | Malignant neoplasm of medulla of right adrenal gland |
| C74.12 | Malignant neoplasm of medulla of left adrenal gland |
| D35.0 | Benign neoplasm of adrenal gland |
| D35.00 | Benign neoplasm of unspecified adrenal gland |
| D35.01 | Benign neoplasm of right adrenal gland |
| D35.02 | Benign neoplasm of left adrenal gland |
| E31.22 | Multiple endocrine neoplasia [MEn] type IIA |
| E31.23 | Multiple endocrine neoplasia [MEn] type IIB |
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