Generic Name: Papaverine Hydrochloride
Class: Vasodilating Agents, Miscellaneous
VA Class: CV900
CAS Number: 61-25-6
Uses for Para-Time SR
Cardiac and Vascular Uses
Has been used IV and intra-arterially in treatment of acute vascular occlusion in conjunction with anticoagulants.a
Has been used in the treatment of other cardiovascular or vascular conditions including vascular encephalopathy associated with hypertensive disease, certain cerebral angiospastic states, and chronic peripheral vascular diseases (i.e., Raynaud’s syndrome, Buerger’s disease); however, use in these conditions has been superseded by more effective agents.a
Has been used alone or in combination with phentolamine and/or alprostadil in patients with neurogenic103 105 106 108 110 112 113 115 116 118 119 120 128 129 132 and/or limited vasculogenic impotence 103 105 106 108 110 112 113 115 116 120 121 128 129 132 or those with psychogenic impotence,105 106 108 120 128 129 132 but efficacy in patients with a vasculogenic component of their impotence may be variable depending on the extent and type of vascular dysfunction.103 108 110 115 120 128 129
Some experts (American Urological Association [AUA]) recommend that selective phosphodiesterase (PDE) type 5 inhibitor therapy (sildenafil, tadalafil, vardenafil) be offered as first-line erectile dysfunction treatment unless contraindicated.178
Intracavernosal therapy with papaverine and/or other drugs generally reserved for patients who do not respond to psychotherapy/behavioral therapy, vacuum constriction devices, and/or selective PDE type 5 inhibitors and in whom attempts at identifying and modifying any drug-related (e.g., certain antihypertensive agents) or other potential reversible medical cause of erectile dysfunction have proved inadequate.110 130
Some clinicians currently prefer alprostadil, alone or combined with other agents, when intracavernosal treatment of impotence is indicated because of possible improved efficacy and decreased adverse effects (e.g., priapism, fibrotic changes) compared with papaverine therapy.130 149 150 151 152 153 154
Choice of therapy for erectile dysfunction should be individualized taking into account differences in response, tolerability and safety, administration considerations, cost and patient reimbursement factors, experience and judgment of the clinician, and individual patient and partner preference, expectations, and satisfaction.170 171 172 173 174 175 176 177 178
Do not use for enhancing erections in men who are not impotent.154
Has been used in the treatment of GI spasms, dysmenorrhea, biliary or ureteral colic, bronchial asthma, cardiac arrhythmias, and other pathologic conditions†;181 a however, insufficient evidence to establish therapeutic value.a
Para-Time SR Dosage and Administration
Has been used intra-arterially in treatment of acute vascular occlusion in conjunction with anticoagulants.a
Rate of Administration
Cardiac and Vascular Use†
IV or IM
6 mg/kg daily (as 4 divided doses).a
Cardiac and Vascular Use
Alternatively, 300 mg (extended-release capsules) every 12 hours.a
75–300 mg (conventional tablets [no longer commercially available in US] 3–5 times daily, also has been used.a
IV or IM
960 mg daily.
Cautions for Para-Time SR
Cardiovascular and Respiratory Effects
Administer IV slowly with caution; rapid injection may result in arrhythmias and fatal apnea.a
Large parenteral doses can depress atrioventricular and intraventricular conduction; may result in serious arrhythmias.180
While some manufacturers have stated that papaverine hydrochloride injection is not indicated for the treatment of impotence via intracorporeal injection,133 134 135 181 the drug has been employed effectively via intracavernosal injection.103 105 106 107 108 110 112 113 114 115 116 118 119 120 121 126 128 130 132 137 142
Do not use vasoactive therapy for impotence in patients who might have conditions predisposing to priapism (e.g., sickle cell anemia or trait, multiple myeloma, leukemia), in those with anatomic deformation of the penis (e.g., angulation, cavernosal fibrosis, Peyronie’s disease), or in men in whom sexual activity is inadvisable or contraindicated.110 143 152 154 164 165 167 Discontinue vasoactive therapy in patients who develop penile angulation, cavernosal fibrosis, or Peyronie’s disease during therapy.143 167
Intracavernosal therapy (administered by self-injection) may be problematic in those receiving anticoagulants, who cannot tolerate transient hypotension, and those with poor manual dexterity, poor vision, or severe psychiatric disease.130
Priapism Associated with Intracavernosal Injection
Consider possibility of persistent priapism (a medical emergency) associated with intracavernosal injection; may require immediate medical and/or surgical intervention.103 105 106 107 108 110 113 115 116 120 122 125 127 129 130 131 132 137 178 181 a (See Advice to Patients.)
Management of priapism includes aspiration of cavernosal blood105 110 113 115 116 120 127 129 and/or intracavernous injection of an α-adrenergic agonist (e.g., metaraminol, phenylephrine) or dopamine.103 105 106 107 108 109 110 111 113 115 120 127 129 137 179 Rarely, more radical therapy for priapism (e.g., cavernospongiosus or Winter’s shunt) may be necessary,104 105 106 110 129 179 such as in patients with persistent priapism (e.g., longer than 24 hours).104 110
Adequate Patient Monitoring
Abuse and Dependence
However, children have received papaverine hydrochloride dosages of 6 mg/kg daily, divided into 4 IM or IV doses.a
Common Adverse Effects
Following oral administration: Nausea,a abdominal distress,180 a anorexia,180 a constipation,180 a malaise,180 a drowsiness,a vertigo,180 a sweating,180 a headache,180 a diarrhea,180 a rash,180 a flushing of the face,180 a increased heart rate,180 a increased depth of respirations,180 a slight increase in BP,180 a sedation.181 a
Following IV administration: General discomfort,181 nausea,181 abdominal discomfort,181 anorexia,181 constipation,181 diarrhea,181 skin rash,181 malaise,181 headache,181 flushing,181 sweating,181 sedation,181 hepatitis,181 hypotension,181 hypertension,181 thrombosis at IV injection site.a
Following intracavernosal administration: Priapism,103 105 106 107 108 110 113 115 116 120 122 125 127 129 130 131 132 137 178 transient pain,105 108 110 129 referred glans pain,108 110 129 burning,103 paresthesia.105 110 129
Interactions for Para-Time SR
Possible increased papaverine effects a
Papaverine may block dopamine receptors and interfere with the therapeutic effects of levodopa a
Avoid concomitant use; do not use in patients with Parkinson's diseasea
Para-Time SR Pharmacokinetics
Readily absorbed from GI tract.a
Oral administration of extended-release capsules may provide continuous drug release over a 12-hour period.a
Distributed throughout the body, with highest concentrations in fat deposits and liver.181
Plasma Protein Binding
For information on systemic interactions resulting from concomitant use, see Interactions.
Spasmolytic effect most pronounced on blood vessels including the coronary, cerebral, pulmonary, and peripheral arteries; also relaxes smooth muscles of the bronchi, GI tract, ureters, and biliary system.180 181 a
In the presence of vascular occlusion, may act by overcoming reflex vasoconstriction in collateral vessels.a
Direct vasodilating action on cerebral blood vessels may explain benefit reported in cerebral vascular encephalopathy.180
Little, if any, analgesic action.a
Advice to Patients
Instruct patients receiving the drug via intracavernosal injection to visit their clinician regularly (e.g., at 3-month intervals) to assess therapeutic benefit, including the need for possible dosage adjustment, and of potential adverse effects associated with such therapy.143 147 159 167
Importance of informing clinicians if risk factors for cardiovascular disease are present prior to initiating any treatment.a
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Papaverine Hydrochloride Capsules ER
Papaverine Hydrochloride Injection (with chlorobutanol 0.5% in multiple-dose vials or preservative-free in single-dose vials)
American Regent, Bedford
AHFS DI Essentials. © Copyright, 2004-2016, Selected Revisions October 1, 2008. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.
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a. AHFS drug information 2007. McEvoy GK, ed. Papaverine. Bethesda, MD: American Society of Health-System Pharmacists; 2007:1796–8.