Dipyridamole

From Anvita Health Wiki

Contents 1 Introduction 2 Indications 3 Contraindications 4 Dosage 5 Pharmacokinetics 6 Adverse-effects 7 Drug-interactions 8 Mechanism-of-action 9 More General Terms 10 Additional Terms 11 Internet Database 12 References

Introduction

• Tradename: Persantine.

Indications

• adjunct to coumadin in prevention of thromboembolic complications of cardiac valve replacement
• used to decrease platelet aggregation in other disorders
• used as diagnostic agent in Persantine stress test to evaluate coronary artery disease in patients unable to exercise

Contraindications

• bronchospasm, severe asthma
• hypotension
• sick sinus syndrome
• AV block (high degree)
  

• pregnancy category = b
• safety in lactation = ?

Dosage

• 75-100 mg PO TID- QID
• ECG stress testing: 0.57 mg/kg over 4 minutes

• Tabs: 25, 50, 75 mg. [1]
• Injection: 5 mg/mL (2 mL)
• Antidote: aminophylline 100 mg IV.

Pharmacokinetics

• incompletely absorbed from the GI tract
• highly bound to plasma proteins, primarily albumin
• 1/2life is 10-12 hours
• metabolized by the liver
• excreted in the bile
  

• elimination via liver
• 1/2life = 8-10 hours

Adverse-effects

• oral [2]

• dizziness
• headache
• abdominal discomfort - diarrhea (common)
• rash

• intravenous [2]

• ventricular fibrillation
• actue myocardial infarction
• transient cerebral ischemia
• chest pain
• flushing
• leg cramps
• dyspepsia
• tachycardia
• anxiety
• neutropenia
• headache
• bronchospasm

• uncommon (< 1%) [3]

• syncope
• vasodilation
• hypertonia
• rhinitis
• edema
• allergic reaction
  
• drug adverse effects of antiplatelet agents

Drug-interactions

• may increase risk of bleeding when administered with heparin
• theophylline & aminophylline antagonize effects of dipyridamole
  
• drug interaction(s) of anti-platelet agents with SSRIs
• drug interaction(s) of antiplatelet agents with proton pump inhibitors
• drug interaction(s) of warfarin with antiplatelet agents

Mechanism-of-action

• dipyridamole dilates normal coronary arteries, but has little effect on stenotic vessels
• inhibition of platelet aggregation
• inhibition of erythrocyte uptake & metabolism of adenosine by inhibiting adenosine deaminase
• inhibition of platelet phosphodiesterase leading to an increased in platelet cAMP
• may stimulate release of prostacyclin or PG2

More General Terms

• antiplatelet agent
• vasodilator agent

Additional Terms

• myocardial perfusion & viability scintigraphy

Internet Database

PubChem: 3108

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
4. UpToDate 13.3 [1]

dipyridamole (Persantine)