In this article, we will discuss Miscellaneous Antimicrobials-Dosage (Part-I). So, let’s get started.
Miscellaneous Antimicrobials
Aztreonam 90-120 mg/kg/day q6-8 hr IV or IM administered by IV bolus over 3-5 min or intermittent infusion over 20-60 min. Bactericidal against enterobacteriaceae and Pseudomonas
aeruginosa but a little or no activity against Gram-positive aerobic bacteria or anaerobic bacteria. Crosses blood-brain barrier and is beta-lactamase stable. Does not cause oto- or nephrotoxicity.
Adult dose: 1 g q 8 hr or 2 g q 12 hr; maximum 8 g/day IM or IV.
Adverse effects: Diarrhea, vomiting, rarely toxic epidermal necrolysis (TEN).
Caution: Not recommended <1 week age.
(Inj azactam, azenam 250 mg, 500 mg, 1 g, 2 g vials).
Chloramphenicol 50-75 mg/kg/day q 8 hr oral. 100 mg/kg/day q 6 hr IV in severe cases. Infants <2 weeks age: 25 mg/kg/day; 2 wks – 1 yr: 50 mg/kg/day.
Adult dose: 50-100 mg/kg/day q 6 hr.
Caution: Monitor blood levels in neonates and maintain between 15 μg and 30 μg/ml.
C/I: Blood dyscrasias, premature infants below 14 days of age, porphyria, hypersensitivity.
Intravenous chloramphenicol use has been associated with development of life-threatening grey baby syndrome. This phenomenon occurs in newborn infants because they do not have fully functional liver enzymes, i.e. UDP-glucuronyl transferase and therefore chloramphenicol remains unmetabolized in the body.
(Chloromycetin, chloramphenicol, paraxin, zitronam, reclor, enteromycetin, vitamycetin caps 250 mg, 500 mg susp 125 mg per 5 ml; inj enteromycetin, paraxin vial 1 g and 2 g per 10 ml).
Colistimethate sulfate/colistin 50,000 to 75,000 iu/kg/day q 8 hr IV for treatment of Gram-negative bacteria including Pseudomonas aeruginosa, Enterobacter, and Klebsiella.
Adverse effects: Nephrotoxicity.
(Inj xylistin, promistin, colymonas, colimed, remergin 1 million iu per vial).
Colistin sodium 2.5-5 mg/kg/day q 6 to 8 hr oral. Use with caution in children below 12 yrs.
Adult dose: 25-100 mg q 8 hr.
Adverse effects: Nephrotoxicity, and neurotoxicity.
(Walamycin, colistop, colistin susp 12.5 mg per 5 ml; walamycin-DS, colistop-DS susp 25 mg per 5 ml).
Daptomycin Used in complicated skin soft tissue infection, and Staphylococcus bacteremia.
Adult dose: 4 mg/kg/day infused over 30 min for 7-14 days. Staphylococcus aureus bacteremia 6 mg/kg/day infused over 30 minutes for 2-6 weeks.
Side effects: GI side effects like nausea, vomiting, diarrhea, dyspepsis, loose stools and abdominal pain, electrolyte imbalance and rarely DRESS syndrome and anaphylaxis, Clostridium difficile-associated diarrhea and colitis. Dose needs to be modified in renal failure. Safety and efficacy in children not proven yet.
(Cubicin, dapmicin, daptocure, emarsa, IV dapt available in powder format 350 mg to be constituted and infused).
Doxycycline hyclate 2-5 mg/kg/day q 12 hr oral. Avoid in children below 8 years of age due to risk of staining of teeth and growth retardation. Tick-borne rickettsia 22 mg/kg/dose q 12 hr.
Adult dose: 200 mg on day 1, then 100 mg daily, 50 mg daily for 6-12 weeks for treatment of acne.
Indication: Chronic bronchitis, brucellosis, chlamydia, mycoplasea, anthrax, lyme disease, granuloma inguinale, rickettsia, ehrlichiosis, cholera, and Cutibacterium acnes. It is also indicated for short-term (<6 weeks) malaria prophylaxis in a dose of 1.5 mg/kg (children above 8 years) and 100 mg o.d. in adults starting 2 days before travel, during stay and 4 weeks after leaving the malarious area.
C/I: Below 8 years, pregnancy and lactation.
Side Effects: Diarrhea, stomach upset, nausea, and itching.
(Cedox DT, biodoxi, doxy-1, doxypal, doxytas, revidox, vibramycin, adoxa, monodox, oracea, lydox, vivocycline, dox-T, minicyclinen, ovadox, nudoxy, tetradox, vibazine DT tabs 100 mg; 200 mg; solomycin 50 mg and 100 mg tabs, minocycline syrup 25 mg, 50 mg per 5 ml).