STREPTOMYCIN SULFATE

STREPTOMYCIN SULFATE (strep-toe-mye'sin) Streptomycin Classifications: aminoglycoside antibiotic; antituberculosis agent; Therapeutic: antibiotic; antituberculosis agent Prototype: Gentamicin Pregnancy Category: C

Availability

400 mg/mL, 1 g injection

Action

Aminoglycoside antibiotic derived from Streptomyces griseus, with bactericidal and bacteriostatic actions. It works by inhibiting bacterial protein synthesis through irreversible binding to the 30S ribosomal subunit of susceptible bacteria. Reportedly, it is the least nephrotoxic of the aminoglycosides.

Therapeutic Effect

Active against a variety of gram-positive, gram-negative, and acid-fast organisms.

Uses

Only in combination with other antitubercular drugs in treatment of all forms of active tuberculosis caused by susceptible organisms. Used alone or in conjunction with tetracycline for tularemia, plague, and brucellosis. Also used with other antibiotics in treatment of subacute bacterial endocarditis due to Enterococci and Streptococci (viridans group) and Haemophilus influenzae and in treatment of peritonitis, respiratory tract infections, granuloma inguinale, and chancroid when other drugs have failed.

Contraindications

History of toxic reaction or hypersensitivity to aminoglycosides; labyrinthine disease; myasthenia gravis; concurrent or sequential use of other neurotoxic or nephrotoxic agents; pregnancy (category C).

Cautious Use

Impaired kidney function (given in reduced dosages); use in older adults and in prematures, neonates, and children.

Route & Dosage

Tuberculosis Adult: IM 15 mg/kg up to 1 g/d as single dose Geriatric: IM 10 mg/kg (max: 750 mg/d) Child: IM 20–40 mg/kg/d up to 1 g/d as single dose Infant: IM 10–15 mg/kg q12h Neonate: IM 10–20 mg/kg q24h Tularemia Adult: IM 1–2 g/d in 1–2 divided doses for 7–10 d Child: IM 20–40 mg/kg/d divided q6–12h Plague Adult: IM 2 g/d in 2–4 divided doses Child: IM 30 mg/kg/d divided q8–12h

Administration

Intramuscular

• Give IM deep into large muscle mass to minimize possibility of irritation. Injections are painful.
• Avoid direct contact with drug; sensitization can occur. Use gloves during preparation of drug.
• Use commercially prepared IM solution undiluted; intended only for IM injection (contains a preservative, and therefore is not suitable for other routes).
• Store ampules at room temperature. Protect from light; exposure to light may slightly darken solution, with no apparent loss of potency.

Adverse Effects (≥1%)

CNS: Paresthesias (peripheral, facial). Body as a Whole: Hypersensitivity angioedema, drug fever, enlarged lymph nodes, anaphylactic shock, headache, inability to concentrate, lassitude, muscular weakness, pain and irritation at IM site, superinfections, neuromuscular blockade, arachnoiditis. GI: Stomatitis, hepatotoxicity. Hematologic: Blood dyscrasias (leukopenia, neutropenia, pancytopenia, hemolytic or aplastic anemia, eosinophilia). Special Senses: Labyrinthine damage, auditory damage, optic nerve toxicity (scotomas). Urogenital: Nephrotoxicity. CNS: Encephalopathy, CNS depression syndrome in infants (stupor, flaccidity, coma, paralysis, cardiac arrest). Respiratory: Respiratory depression. Skin: Skin rashes, pruritus, exfoliative dermatitis.

Diagnostic Test Interference

Streptomycin reportedly produces false-positive urinary glucose tests using copper sulfate methods (Benedict's solution, Clinitest) but not with glucose oxidase methods (e.g., Clinistix, TesTape). False increases in protein content in urine and CSF using Folin-Ciocalteau reaction and decreased BUN readings with Berthelot reaction may occur from test interferences. C&S tests may be affected if patient is taking salts such as sodium and potassium chloride, sodium sulfate and tartrate, ammonium acetate, calcium and magnesium ions.

Interactions

Drug: May potentiate anticoagulant effects of warfarin; additive nephrotoxicity with acyclovir, amphotericin B, aminoglycosides, carboplatin, cidofovir, cisplatin, cyclosporine, foscarnet, ganciclovir, salicylates, tacrolimus, vancomycin.

Pharmacokinetics

Peak: 1–2 h. Distribution: Diffuses into most body tissues and extracellular fluids; crosses placenta; distributed into breast milk. Elimination: In urine. Half-Life: 2–3 h adults, 4–10 h newborns.

Nursing Implications

Assessment & Drug Effects

• Lab tests: Obtain C&S tests prior to and periodically during course of therapy. In patients with impaired kidney function, frequent determinations of serum drug concentrations and periodic kidney and liver function tests are advised (serum concentrations should not exceed 25 mcg/mL in these patients).
• Be alert for and report immediately symptoms of ototoxicity (see Appendix F). Symptoms are most likely to occur in patients with impaired kidney function, patients receiving high doses (1.8–2 g/d) or other ototoxic or neurotoxic drugs, and older adults. Irreversible damage may occur if drug is not discontinued promptly.
• Early damage to vestibular portion of eighth cranial nerve (higher incidence than auditory toxicity) is initially manifested by moderately severe headache, nausea, vomiting, vertigo in upright position, difficulty in reading, unsteadiness, and positive Romberg sign.
• Be aware that auditory nerve damage is usually preceded by vestibular symptoms and high-pitched tinnitus, roaring noises, impaired hearing (especially to high-pitched sounds), sense of fullness in ears. Audiometric test should be done if these symptoms appear, and drug should be discontinued. Hearing loss can be permanent if damage is extensive. Tinnitus may persist several days to weeks after drug is stopped.
• Monitor I&O. Report oliguria or changes in I&O ratio (possible signs of diminishing kidney function). Sufficient fluids to maintain urinary output of 1500 mL/24 h are generally advised. Consult physician.

Patient & Family Education

• Report any unusual symptoms. Review adverse reactions with physician periodically, especially with prolonged therapy.
• Be aware of possibility of ototoxicity and its symptoms (see Appendix F).
• Report to physician immediately any of the following: Nausea, vomiting, vertigo, incoordination, tinnitus, fullness in ears, impaired hearing.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug