Anti-platelets/ Anti-coagulants

Mild to moderate pain: Headaches and transient musculoskeletal pain. Pyrexia and anti-platelet action.

Irreversible inactivation of the COX-1 enzyme required for prostaglandin and thromboxane synthesis. Blocking Thromboxane A2 prevent platelet aggregation.

• Children <16 years.
• Peptic ulceration (past and active)
• Haemophilia

• NSAID sensitivity
• Avoid in hepatic and renal impairment.
• Avoid towards end of pregnancy or whilst breastfeeding.

• GI irritation.
• Increased bleeding time.
• Bronchospasm
• Skin reactions

Oral: 300-900mg every 4-6 hours (max 4g)

Rectal: 450-900mg every 4 hours (max 3.6g)

• For long-term anti-platelet action:
• 75mg OD

Take after food or enteric coated capsules (slower delivery)

Use with other NSAIDs can increase side effects.

Increased risk of bleeding if given with anticoagulants, antidepressants, clopidogrel, steroids, iloprost

Anti-platelet activation:

Preventing atherothrombotic event in arterial disease, post-MI or stroke, or during active ACS event.

Irreversibly inhibits binding of ADP to a receptor on platelets, inhibiting activation and up-regulation of GP IIb/IIIa receptors which prevents platelet aggregation

Active bleeding

Caution in hepatic and renal impairment, or at risk of bleeding

Avoid in Pregnancy/ breastfeeding

GI discomfort, Bleeding and rare neutropenia

Due to MOA it can take several days for anti-platelet effects to wear off.

• Oral preparations
• Prevention: 75mg OD

ACS: 300mg then 75mg daily (600mg loading dose in STEMI)

LMWH

Same efficacy and longer action, but reduced risk of heparin-induced thrombocytopenia

• Venous Thromboprophylaxis
• DVT and PE treatment

Accelerates action of anti-thrombin III, increasing the inactivation of Factor Xa (prevents conversion of prothrombin to thrombin)

Protamine (50mg max)

In VTE prophylaxis: 1.5mg/kg OD sub-cut for 5/7

For NSTEMI/UA: 1mg/kg BD

For STEMI: none if patient is for PCI

Heparin-induced thrombocytopenia and thrombosis syndrome

NEVER!

Tinzaparin, Dalteparin

Inhibits Vitamin K reductase, preventing activation of Factors 10, 9, 7, 2 and therefore blood coagulation

DVT, PE, AF and prosthetic valves if at risk of embolisation

• Pregnancy
• Bleeders
• Active Ulcers

• Takes >3 days for therapeutic effect.
• LMWH cover should be given until this is reached as it may leave the patient in a pro-thrombotic state.

Bleeding, N+V, Diarrhoea, Jaundice, liver dysfunction, pancreatitis, pyrexia, alopecia, 'purple toes'

CHADS VASC score

2-3

• FBC
• LFT
• INR

70

1) Rapid in-patient

2) Rapid out-patient

3) Slow out-patient

Many! See BNF