New drugs in dermatology (Proceedings)


New drugs in dermatology (Proceedings)

Aug 01, 2011

In the field of veterinary medicine we see a constant search for newer, more effective, and convenient but inexpensive drugs with lesser side effects. Not only new drugs are interesting, but old drugs are occasionally rediscovered for new indications. Although many of the new approved drugs available have been thoroughly investigated, reports of the use of older drugs or the use of newer drugs for a different indication are often based on anecdotal reports and need to be further investigated in controlled studies.

Cefovecin sodium (Convenia® Pfizer; 80 mg/ml)

     • This is a semi-synthetic cephalosporin with bactericidal effect which inhibits bacterial cell wall syntheses and is relatively resistant to bacterial beta-lactamases. Its main antibacterial spectrum is: gram-negative bacteria (E. coli, Proteus, Klebsiella), gram-positive bacteria (Staphylococci & Streptococci.). Cefpodoxime is not effective against Pseudomonas aeruginosa, Enterococci and methicillin-resistant Staph. Poor efficacy has been shown against anaerobes.
     • Indication
          o Dogs: skin infections (pyoderma, wounds, abscesses) with Staphylococcus intermedius and Streptococcus canis
          o Cats: infections with Pasteurella multocida
     • Occasional GI signs (vomiting, diarrhea) may be seen.
     • Dosage: 8 mg/kg subcutaneous. Injection can be repeated after 7 to 14 days (very convenient!)

Cefpodoxime proxetil (Simplicef® Pfizer; 100 mg, 200 mg)

     • This 3rd generation cephalosporin (antimicrobial activity, see Cefovecin)
     • Indication: skin infections (pyoderma, wounds, abscesses) in dogs.
     • Drug is well tolerated. Occasionally GI signs may occur.
     • Dosage: 5-10 mg/kg orally every 24 hours

Chloramphenicol (Duricol®; 50 mg, 100 mg or Viceton®; 250 mg, 500 mg)

     • Broad spectrum antibiotic inhibiting bacterial protein synthesis. Gram-positive aerobic organisms (Streptococci, Staphylococci) are generally susceptible, and many anaerobic bacteria (Clostridium, Bacteroides, Fusobacterium) and organisms such as Nocardia, Mycoplasma, and Rickettsia are sensitive to chloramphenicol.
     • Indication: methicillin-resistant Staph. spp. infections
     • Usually well tolerated but dose-related bone marrow suppression (reversible) is occasionally seen with longterm use, as well as GI signs.
     • Dosage: 30-50 mg/kg orally every 8 hours
     • Caution: Can cause irreversible anaplastic anemia in humans!

Cyclosporine (Atopica® Novartis; 25 mg, 50 mg, 100 mg; Neoral®; 100 mg/ml)

     • CsA is a naturally produced (fungus: Tolypocladium inflatum) calcineurin inhibitor with anti-inflammatory and immunosuppressive properties focused on cell-mediated immune response.
     • Indication: Perianal fistula, canine atopic dermatitis; may also be used for maintenance of auto-immune diseases (e.g. pemphigus foliaceus)
     • Since CsA is mainly metabolized through the liver it should be used with caution in patients with liver disease. Many drugs are metabolized through the same cytochrome P450 enzyme system and are able to reduce the metabolism of CsA. The use of ketoconazole at 5 mg/kg orally per day may help to reduce the CsA dose by up to 50%.
     • The most common side effects are vomiting, anorexia and diarrhea.
     • Dosage: 5 mg/kg orally every 24 hours

Tacrolimus (Protopic®; 0.1% or 0.3% ointment)

     • This is a topical calcineurin inhibitor with similar mechanism as cyclosporine. Advantage of calcineurin inhibitors compared to steroids is their lack of cutaneous atrophy and metabolic effects.
     • Indication: localized atopy, discoid lupus erythematosus (DLE), pemphigus erythematosus (PE), pemphigus foliaceus (PF), cutaneous idiopathic vasculitis, alopecia areata, Vitiligo. May be also used for maintenance of perianal fistula.
     • Increased erythema and irritation can occasionally be observed after starting therapy, but the reaction is transient.
     • Dosage: apply daily on affected skin area.