Staphylococcus aureus, or staph, is a bacteria that can cause a multitude of diseases in humans. Infections can affect the skin, lungs, heart, bones and blood. Antibiotics are the mainstay of treatment against staph infections; oral antibiotics are usually prescribed for 10 to 14 days. If the condition of the patient is severe, as in case of heart and blood infection, however, antibiotics may initially be administered intravenously.
Penicillins
Penicillin has traditionally been used to treat staph infections. Most strains of Staphylococcus prevalent today, however, produce enzymes called penicillinase which inactivate penicillin thereby, making the bacteria resistant to the antibiotic. In an article published in August 2000 by the online journal "American Family Physician," Dr. Keith Holten states that penicillinase-resistant penicillins such as cloxacillin, nafcillin, oxacillin and dicloxacillin have been developed to treat such staph infections.
Penicillinase-resistant penicillins are absorbed well when taken orally and should be taken one to two hours before meals. These antibiotics are primarily prescribed for the treatment of skin and soft tissue infections.
Another antibiotic that is available in an oral combination with a penicillinase inhibitor is amoxicillin-clavulanate; it may be the first choice for the treatment of infections of the ear, sinuses, urinary tract and skin.
Precautions should be taken as penicillin allergies are common. It can also cause renal impairment in rare cases.
Cephalosporins
First-generation cephalosporins such as cefadroxil, cephalexin and cephradine can be used to treat skin and soft tissue infections caused by Staphylococcus aureus, especially the methicillin-resistant strains. Holten states that these antibiotics are preferred for oral administration due to a lower incidence of gastrointestinal side effects and better taste.
Allergies are less common in this class of antibiotics, but individuals with renal impairment and pregnant women should be cautious.
Macrolides
Macrolides have traditionally been used to treat staph infections of skin and ears. Research by Franz-Josef Schmitz published in 2000 in the "Journal of Antimicrobial Chemotherapy," however, demonstrates that there's a rising resistance to macrolides such as erythromycin. This is especially true among methicillin-resistant Staphylococcus aureus, or MRSA.
Macrolides are best absorbed when taken by mouth on an empty stomach. Common side effects include nausea, vomiting, stomach pain and loss of appetite.
Vancomycin
Vancomycin has gained importance in recent times due to its effectiveness against MRSA. The antibiotic is available in capsule and suspension form. MayoClinic.com warns that bitter or unpleasant taste, mouth irritation and nausea or vomiting may occur in some patients taking vancomycin.
Trimethoprim/ Sulfamethoxazole
According to the Oregon Health and Science University, trimethoprim/sulfamethoxazole, or TMP-SMX, is considered an alternative to vancomycin in non-endocarditis patients with susceptible strains of MRSA. Nausea, vomiting, and headaches are common side effects.
In patients with orthopedic implants, long-term use of high dosages of TMP-SMX carry the risk of serious side effects such as blood in the urine, a stiff neck or seizures; however, it may be a suitable option when other treatments are not possible.
References
- "American Family Physician"; Appropriate Prescribing of Oral Beta-Lactam Antibiotics; Keith B. Holten and Edward M. Onusko; August 2000
- "Journal of Antimicrobial Chemotherapy"; Prevalence of Macrolide-resistance Genes; Franz-Josef Schmitz et al; June 2000
- MayoClinic.com: Vancomycin
- Oregon Health and Science University: Oral Trimethoprim-Sulfamethoxazole
