Streptomycin warnings and precautions

# Warnings

### Ototoxicity
Both vestibular and auditory dysfunction can follow the administration of streptomycin. The degree of impairment is directly proportional to the dose and duration of streptomycin administration, to the age of the patient, to the level of renal function and to the amount of underlying existing auditory dysfunction. The ototoxic effects of the aminoglycosides, including streptomycin, are potentiated by the co-administration of ethacrynic acid, mannitol, furosemide and possibly other diuretics.
The vestibulotoxic potential of streptomycin exceeds that of its capacity for cochlear toxicity. Vestibular damage is heralded by headache, nausea, vomiting and disequilibrium.
Early cochlear injury is demonstrated by the loss of high frequency hearing. Appropriate monitoring and early discontinuation of the drug may permit recovery prior to irreversible damage to the sensorineural cells.

### Pregnancy
Streptomycin can cause fetal harm when administered to a pregnant woman. Because streptomycin readily crosses the placental barrier, caution in use of the drug is important to prevent ototoxicity in the fetus. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

### Clostridium difficile associated diarrhea (CDAD)
Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Streptomycin for Injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difjicile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

# Precautions

### General
Prescribing streptomycin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
Baseline and periodic caloric stimulation tests and audiometric tests are advisable with extended streptomycin therapy. Tinnitus, roaring noises, or a sense of fullness in the ears indicates need for audiometric examination or termination of streptomycin therapy or both.
Care should be taken by individuals handling streptomycin for injection to avoid skin sensitivity reactions. As with all intramuscular preparations, Streptomycin Sulfate Injection should be injected well within the body of a relatively large muscle and care should be taken to minimize the possibility of damage to peripheral nerves. (See DOSAGE AND ADMINISTRATION.)
Extreme caution must be exercised in selecting a dosage regimen in the presence of pre-existing renal insufficiency. In severely uremic patients a single dose may produce high blood levels for several days and the cumulative effect may produce ototoxic sequelae. When streptomycin must be given for prolonged periods of time alkalinization of the urine may minimize or prevent renal irritation.
A syndrome of apparent central nervous system depression, characterized by stupor and flaccidity, occasionally coma and deep respiratory depression, has been reported in very young infants in whom streptomycin dosage had exceeded the recommended limits. Thus, infants should not receive streptomycin in excess of the recommended dosage.
In the treatment of venereal infections such as granuloma inguinale, and chancroid, if concomitant syphilis is suspected, suitable laboratory procedures such as a dark field examination should be performed before the start of treatment, and monthly serologic tests should be done for at least four months.
As with other antibiotics, use of this drug may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, appropriate therapy should be instituted.

### Information for Patients
Patients should be counseled that antibacterial drugs including streptomycin should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When streptomycin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by streptomycin or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose ofthe antibiotic. If this occurs, patients should contact their physician as soon as possible.

### Pregnancy Category: D
See WARNINGS section.

### Nursing Mothers
Because of the potential for serious adverse reactions in nursing infants from streptomycin, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

### Pediatric Use
(See DOSAGE AND ADMINISTRATION.)