Dosing and uses of ParaTime SR (papaverine)
Adult dosage forms and strengths
capsule, extended release
- 150mg
injectable solution
- 30mg/mL
Arterial Spasm
Sustained release oral formulation: 150 mg PO q8-12hr OR 300 mg PO q12hr
Injection solution: 30-65 mg (up to 120 mg if needed) IV/IM; may repeat q3hr
Cardiac extrasystoles: Administer 2 doses 10 minutes apart
Admin IV by slow push (1-2 minutes)
Other Indications & Uses
Relief of cerebral & peripheral ischemia associated with arterial spasm, & MI complicated by arrhythmias
Increase collateral circulation in treatment of acute vascular occlusion
Historical uses (no longer recommended as first-line treatment): Angina, vascular encephalopathy, cerebral angiospasm, chronic peripheral vascular disease, GI spasm, dysmenorrhea, biliary colic, bronchial asthma
Off-label: Erectile dysfunction (intracavernosal inj)
Pediatric dosage forms and strengths
capsule, extended release
- 150mg
injectable solution
- 30mg/mL
Arterial Spasm
6 mg/kg/day IV/IM divided q6hr
Administer IV by slow push (1-2 minutes)
Geriatric dosage forms and strengths
Arterial Spasm
Sustained release oral formulation: 150 mg PO q8-12hr OR 300 mg PO q12hr
Injection solution: 30-65 mg (up to 120 mg if needed) IV/IM; may repeat q3hr
Cardiac extrasystoles: Administer 2 doses 10 minutes apart
Admin IV by slow push (1-2 minutes)
ParaTime SR (papaverine) adverse (side) effects
Frequency not defined
BP changes
Flushing
Tachycardia
Depression
Dizziness
HA
Drowsiness
Malaise
Raised intracranial pressure
Pruritus
Rash
Anorexia
Diarrhea
Dry mouth
Constipation
Nausea
Vomiting
Hepatitis (rare)
Cirrhosis (rare)
Priapism (with intracavernosal inj)
Sweating
Warnings
Contraindications
Hypersensitivity
Complete AV block
Cautions
Rapid inj may cause fatal apnea
Glaucoma, cardiac conduction disorder
Intracavernosal inj may lead to priapism
Chronic use may lead to dependence due to CNS depressant effect
Discontinue if signs or symptoms of hepatic hypersensitivity
Pregnancy and lactation
Pregnancy category: C
Lactation: unknown; use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of ParaTime SR (papaverine)
Mechanism of action
Synthetic derivative of opium
Smooth muscle spasmolytic via inhibition of oxidative phosphorylation & interference with Ca++ during muscle contraction as well as increase in cAMP from inhibition of cyclic nucleotide phosphodiesterase; most pronounced effect on blood vessels, including coronary, cerebral, pulmonary, gastrointestinal sphincter relaxation & peripheral arteries
Depresses cardiac muscle excitability
Pharmacokinetics
Onset: Rapid
Duration: PO: 12 hr
Protein Bound: 90%
Half-life elimination: 0.5-1.5hr
Metabolism: Liver, via glucuronidation
Excretion: Urine
Administration
IV Incompatibilities
Solution: Lr
Additive: aminophylline with trimecaine
Syringe: diatrizoate meglumine/diatrizoate sodium, ioxaglate meglumine/ioxaglate sodium
IV Compatibilities
Solution: dextrose solutions, fructose solutions, saline, dextrose-saline, Ringer's, Na-lactate 1/6m
Additive: theophylline
Syringe: iohexol, iopamidol, phentolamine
IV/IM Administration
IM or slow IV over 1-2 min
Storage
Store vial at room temp, do not freeze
Protect from light
