Antiplatelet agents iinclude- Dipyridamole, Ticlopodine, Abciximab Refer - Dipyridamole

Interacting drugs- summary

Dipyridamole+

Indomethicin                                                                                                        coadminstration may augument water retension

NSAIDs                                                                                                                           indomethicin and dipyridamole coadministration may agument water retention.

+Antiplatelet agents

 Epoprostenol                                                                                                         coadministration can increase the risk of bleeding, although this did not occur in clinical trials 

Chronic angina pectoris 

Worsening of angina and cardiac arrhythmias when given I.V. GI disturbances,dizziness, headache, faintness,facial flushing skin rash,excess dose may lower B.P. Angina.

Known hypersensitivity,peptic ulcer.

Special precautions:

In patients in rapidly worsening angina,subvalvular aortic stenosis,hemodynamic instabillity associated with myocardial infaction and coagulation disorders when given I.V.during myocardial imaging.

Use in the 1st trimester of pregnancy not recommended.

Indications:

Chronic angina pectoris

Dosage:

50mg 3 times a day, at least one hour before meals.

Missed dose-

1. If you miss a dose of this medicine, and remember within 6 hours of take it as soon as possible unless the dose is less than 4 hours.

2. However, if you do not remember until later, skip the missed dose and go back to your regular dosing schedule.

3. Do not double doses.

EVIDENCE BASED MEDICINE (April 2003)

Stroke prevention

Comparative effectiveness of various interventions

PRIOR TO STROKE OR TRANSIENT ISCHAEMIC ACCIDENT (TIA)

Beneficial

1. Antiplatelet treatment

2. Cholestrerol reduction (for those patients who also have coronary heart disease)

3. Carotid endarterectomy (in patients with severe symptomatic carotid artery stenosis)

Unknown effectiveness

1. Cholesterol reduction (for patients without CHD)

2. Blood pressure reduction

3. Carotid endarterectomy (in patients with severe symptomatic carotid artery stenosis)

4. Catotid angioplasty

Likely to ineffective or even harmful

1. Oral anticoagulation

ATRIAL FIBRILLATION AND A PRIOR STROKE OR TIA

Beneficial

1. Oral anticoagulation

2. Aspirin for patients with contraindications to an anticoagulant

ATRIAL FIBRILLATION BUT NO OTHER MAJOR RISK FACTORS FOR STROKE

Likely to be beneficial

1. Oral anticoagulation

2. Aspirin for patients with contraindications to an anticoagulant

KEY POINTS

In patients with a prior stroke or TIA

1. Insufficient evidence to support routine blood presure reduction

2. Statins may prevent stroke in those with a history of CHD but evidence inconclusive in those with no history of CHD.

3. Routine use of prolonged anti-platelet treatment beneficial ( if no contraindication)

4. Aspirin 75mg daily as effective as higher doses. No evidence that any other antiplatelet regimen is definitely superior in the prevention of vascular events. Clopidogrel or the combination of asprin and dipyridamole are safe and effective (but more costly) alternatives to aspirin

5. No evidence of benefit from anti-coagulation in patients in sinus rhythm, but an increased risk of serious bleeding

6. Carotid endarterectomy reduces risk of major stroke in patients with severe carotid stenosis provided the risks of imaging and surgery are small.

7. Percutaneous transluminal angioplastys role has not been evaluated adequately In patients with atrial fibrillation and a pror stroke or TIA- 

1. Anticoagulants reduce risk of stroke, provided there is low risk of bleeding and careful monitoring

2. Aspirin reduces risk of stroke but less effectively than anticoagulants. These findings support the use of aspirin among patients with atrial fibrillation and contra-indication to anticoagulants In patients with atrial fibrillation but neither major risk factors for stroke

1. Anticoagulants are of net benefit, if low risk of bleeding and careful monitoring

2. Aspirin is a reasonable alternative in patients with contra-indications to anticoagulants

DYPYRIDAMOLE

1. Allergies- Tell your doctor if you have ever had any unusual or allergic reactions to dipyridamole other related medicines. Also tell your doctor if youn are allergic to any other substances such as foods, preservatives or dyes.

2. Pregnancy- dipyradamole has not shown to cause birth defects or other problems in mice, rats or rabbits given many times the the maximum human dose

3. Breast feeding- although small amounts of dipyridamole medicines pass into the breast milk they have not been reported to cause problems in nursing babies.

4. Children- no specific information available comparing use of dipyridamole in childrern with use in other groups

5. Elderly- signs and symptoms of overdose may be especialy likely to occur in elderly patients

6. Other medicines- tell your doctor if you are taking any of the following-

Aminophylline or Caffeine or Dyphylline or Oxtriphylline or Theophylline - these medicines will interefer with the result of this test. Caffeine should not be taken for 8 to 12 hours before the test. the other medicines listed arte are used to treat asthma. They should not be taken for about 36 hours before the test. However do not stop taking m,edicine on your own. Anticoagulants or Aspirin or Carbenicillin or Cefamandole or Cefoperazone or Cefetetan or Divalproex or Heparin or Inflammation or pain medicine or Pentoxifyline or Plicamycin or Sulfinpyrazone or Ticarcillin or Ticlopodine or Valproic acid- chance of bleeding may be increased

7.Other medical problems- tell your doctor if you have any other medical problems- Asthma or Chest pain - chance of side effects may be increased Low blood pressure - large amount of dypridamole can make your condition worse

8. Missed dose- If you miss a dose of this medicine take it as soon as possible. However if it is almost time for your next dose go back to your regular dosing schedule. Do not double doses.

9. Storage - Keep out of reach of children. Store away from heat or direct sunlight. Do not store the capsule in bathroom, near the kitchen sink, or in other damp places.

10. Outdated medicines - Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of reach of children.

Pharmacology:

Dipyridamole lengthens abnormally shortened platelet survival time in dose-dependendent manner. Dipyridamole is a platelet adhesion inhibitor,although the mechanism of action has not been fully elucidated

Pharmacokinetics:

Following an oral dose of dipyridamole the average time to peak concentration is about 75 minutesThe alpha half life(the initial decline following peak concentration)is about 40 minutes. The beta half-life (the treminal decline in plasma concentration)is about

None reported

Pregnancy:

Use during pregnancy only if clearly needed

Lactation:

Excercise caution when administering to a nursing woman