Drugs acting on blood components / toxic products

The principal drugs affecting blood components to relieve Raynaud's disease are the E and F class prostaglandins and the prostacyclins. All are believed to act by vasodilation.

Iloprost, a synthetic analogue of prostacyclin, is the key clinical example:

• additional advantages include inhibition of platelet aggregation and increased red cell deformability
• it raises the temperature of the hands and fingers, and brings about pain relief in small scale, double blind trials
• requires hospitalisation for IV administration, but the effects can last for up to 16 weeks
• has been shown to be effective in patients with Raynaud's secondary to systemic sclerosis (1)
• the efficacy of the oral formulation is controversial (2)

Evening primrose oil (concentrated linoleic and gamolenic acids) and fish oil (omega-3 marine triglycerides) are metabolised to prostaglandin and prostacyclin-like elements

• increasing prostacyclins via therapy with gamolenic acid (GLA) has been demonstrated to raise the temperature of the hands and fingers, and bring about pain relief in small scale, double blind trials - a dose of 320mg of GLA per day is recommended (2)
  • most capsules of evening primrose oil etc., only contain approximately 40mg of GLA. Therefore one would need to take 4 capsules twice a day. Generic GLA (320mg per day) or another alternative is Omacor (R) (2000-4000mg per day) can be prescribed

The steroid, stanozolol, and the thromboxane-A2-receptor antagonist, dazoxiben, have not as yet proved to be efficacious in trials.

Reference:

• 1. Milio G. et al. Iloprost treatment in patients with Raynaud's phenomenon secondary to systemic sclerosis and the quality of life: a new therapeutic protocol. Rheumatology 2006 45(8):999-1004
• 2. Block JA, Sequeria W.. Raynaud's Phenomenon. Lancet 2001; 357 (9273):2042-8.
• 3.. Raynaud's & Scleroderma association. Raynaud's & Scleroderma - An update for GP's (2009).