Antimalarial

Antimalarial drugs have the obvious connotation of therapeutic utility against malaria, but certain drugs with activity against malaria also are immunomodulators used in rheumatology.

In general usage, the term applies specifically to synthetic analogs of quinine, rather than antibiotics or other drugs with activity against malarial parasites and other protozoa. The major drugs of this type are:

• 4-aminoquinolone derivatives
  • Hydroxychloroquine
  • Chloroquine
• 9-aminoacridine derivatives
  • Quinacrine

Treatment of malaria

For malaria, chloroquine is the most important drug; quinacrine is no longer in commercial tablet production but, as a third-line agent, is available from compounding pharmacies. Chloroquine remains the drug of choice for chemoprophylaxis when resistance has not been reported.

Rheumatology

These are examples of disease-modifying antirheumatic drugs (DMARD), which directly affect the disease process rather than simply providing pain control. Their most important use was in systemic lupus erythematosis, although monoclonal antibodies are now the first-line drugs. They also have applicability to rheumatoid arthritis, palindromic arthritis and psoriatic arthritis. When DMARDs are indicated, other DMARDs are often preferred, such as methotrexate in rheumatoid arthritis.

In a 1998 study comparing chloroquine and hydrochloroquine, hydroxychloroquine was less toxic but less effective than chloroquine, but there were no firm recommendations of one over the other. Hydroxychloroquine is considerably more expensive.

Side effects

Damage to the eyes are the greatest concerns. These drugs may deposit in the melanin of the pigmented epithelial layer of the retina. Since early damage is often reversible, thorough opthalmologic examination is advised every 6 to 12 months.