Dipyridamole
Dipyridamole (Persantine)
Dipyridamole
(dye=peer- ID-ah-mohl))
Pregnancy Category: B Apo-Dipyridamole FC Apo-Dipyridamole SC Novo-Dipiradol Persantine (Rx)

Classification: Platelet adhesion inhibitor

Action/Kinetics: In higher doses may act by several mechanisms, including inhibition of red blood cell uptake of adenosine, itself an inhibitor of platelet reactivity; inhibition of platelet phosphodiesterase, which leads to accumulation of cAMP within platelets; direct stimulation of release of prostacyclin or prostaglandin D ₂; and/or inhibition of thromboxane A ₂ formation. Dipyridamole prolongs platelet survival time in clients with valvular heart disease and has maintained platelet count in open heart surgery. Also causes coronary vasodilation which may be due to inhibition of adenosine deaminase in the blood, thus allowing accumulation of adenosine which is a potent vasodilator. Vasodilation may also be caused by delaying the hydrolysis of cyclic 3',5'-adenosine monophosphate as a result of inhibition of the enzyme phosphodiesterase. Incompletely absorbed from the GI tract. Peak plasma levels, after PO: 45-150 min. t 1/2, after PO: initial 40-80 min; terminal 10-12 hr. Metabolized in the liver and mainly excreted in the bile.

Uses: PO. As an adjunct to coumarin anticoagulants in preventing post-operative thromboembolic complications of cardiac valve replacement. With aspirin to reduce the risk of stroke in clients who have had a stroke or a TIA previously. IV. As an alternative to exercise in thallium myocardial perfusion imaging for the evaluation of CAD in those who cannot exercise adequately. Investigational: Alone or as an adjunct to treat angina, to prevent graft occlusion in those undergoing arterial reconstructive bypass surgery, intralingual bypass grafts, and to prevent deterioration of coronary vessel patency after percutaneous transluminal angioplasty. Use with aspirin for preventing migraine headaches, MI, to reduce platelet aggregation at the carotid endarterectomy, to slow progression of peripheral occlusive arterial disease, to reduce incidence of DVT, to reduce the number of platelets deposited on dacron aortofemoral artery grafts, and TIAs.
NOTE: Not effective for the treatment of acute episodes of angina and is not a substitute for the treatment of angina pectoris.

Special Concerns: Use with caution in hypotension and during lactation. Safety and efficacy have not been determined in children less than 12 years of age.

Side Effects: After PO use. GI: GI intolerance, N&V;, diarrhea. CNS: Dizziness, headache, syncope. CV: Peripheral vasodilation, flushing. Rarely, angina pectoris or aggravation of angina pectoris (usually at the beginning of therapy). Miscellaneous: Weakness, rash, pruritus.
After IV use. Most common side effects (1% or greater) are listed. GI: Nausea, dyspepsia. CNS: Headache, dizziness, paresthesia, fatigue. CV: Chest pain, angina pectoris, ECG abnormalities (ST-T changes, extrasystoles, tachycardia), precipitation of acute myocardial ischemia in clients with CAD, hypotension, flushing, blood pressure lability, hypertension. Miscellaneous: Dyspnea, unspecified pain.

Overdose Management: Symptoms: Hypotension of short duration. Treatment: Use of a vasopressor may be beneficial. Due to the high percentage of protein binding of dipyridamole, dialysis is not likely to be beneficial.

Drug Interactions: Evening primrose oil / Potential for antiplatelet effect Feverfew / Potential for antiplatelet effect Garlic / Potential for antiplatelet effect Ginger / Potential for antiplatelet effect Ginkgo biloba / Potential for antiplatelet effect Ginseng / Potential for antiplatelet effect Grapeseed extract / Potential for antiplatelet effect

How Supplied: Injection: 5 mg/mL; Tablets: 25 mg, 50 mg, 75 mg.

Dosage
?Tablets Adjunct in prophylaxis of thromboembolism after cardiac valve replacement.
Adults: 75-100 mg q.i.d. as an adjunct to warfarin therapy.
Prevention of thromboembolic complications in other thromboembolic disorders.
Adults: 150-400 mg/day in combination with another platelet-aggregation inhibitor (e.g., aspirin) or an anticoagulant.
?IV Adjunct to thallium myocardial perfusion imaging.
Adjust the dose according to body weight. Recommended dose is 0.142 mg/kg/min infused over 4 min. Total dose should not exceed 60 mg.