MINOCYCLINE HYDROCHLORIDE

MINOCYCLINE HYDROCHLORIDE (mi-noe-sye'kleen) Arestin, Dynacin, Minocin Classifications: tetracycline antibiotic; Therapeutic: antibiotic; tetracycline Prototype: Tetracycline Pregnancy Category: D

Availability

50 mg, 75 mg, 100 mg capsules; 50 mg, 75 mg, 100 mg tablets; 50 mg/5 mL suspension; 1 mg sustained release microspheres

Action

Semisynthetic tetracycline derivative which appears to be active against strains of Staphylococci resistant to other tetracyclines; photosensitivity occurs only rarely. Bacteriostatic action appears to be a result of reversible binding to ribosomal units of susceptible bacteria and inhibition of bacterial protein synthesis.

Therapeutic Effect

Effective against gram-positive and gram-negative bacteria, but usually use against gram-negative bacteria. Effective against Mycobacterium marinum infections, U. urealyticum, N. gonorrhoeae.

Uses

Treatment of mucopurulent cervicitis, granuloma inguinale, lymphogranuloma venereum, proctitis, bronchitis, lower respiratory tract infections caused by Mycoplasma pneumoniae, Rickettsial infections, chlamydial infections, non-gonococcal urethritis, chlamydial conjunctivitis, plague, brucellosis, bartonellosis, tularemia, UTI, and prostatitis; acne vulgaris, gonorrhea, cholera, meningococcal carrier state.

Contraindications

Hypersensitivity to tetracyclines; oral administration in meningococcal infections; sunlight (UV) exposure; pregnancy (category D), lactation, children <8 y.

Cautious Use

Renal and hepatic impairment; older adults.

Route & Dosage

Antiinfective Adult: PO 200 mg followed by 100 mg q12h Child (>8 y): PO 4.4 mg/kg followed by 2 mg/kg q12h Acne Adult: PO 50 mg 1–3 times/d Meningococcal Carrier State Adult: PO 100 mg q12h x 5 d Child (>8 y): PO 4 mg/kg followed by 2 mg/kg q12h x 5 d (max: 100 mg/dose)

Administration

Oral

• Shake suspension well before administration.
• Oral therapy is the preferred route; institute as soon as possible.
• Check expiration date. Outdated tetracycline can cause severe adverse effects.

Adverse Effects (≥1%)

CNS: Weakness, light-headedness, ataxia, dizziness, or vertigo. GI: Nausea, cramps, diarrhea, flatulence. Hepatic: Hepatitis, liver enzyme increases, hepatotoxicity.

Interactions

Drug: antacids, iron, calcium, magnesium, zinc, kaolin and pectin, sodium bicarbonate, bismuth subsalicylate can significantly decrease minocycline absorption; effects of both desmopressin and minocycline antagonized; increases digoxin absorption, increasing risk of digoxin toxicity; methoxyflurane increases risk of kidney failure. Food: Dairy products significantly decrease minocycline absorption; food may also decrease its absorption.

Pharmacokinetics

Absorption: 90–100% from GI tract. Peak: 2–3 h. Distribution: Tends to accumulate in adipose tissue; crosses placenta; distributed into breast milk. Metabolism: Partially metabolized. Elimination: 20–30% in feces; 12% in urine. Half-Life: 11–26 h.

Nursing Implications

Assessment & Drug Effects

• Obtain history of hypersensitivity reactions prior to administration; drug is contraindicated with known tetracycline hypersensitivity.
• Lab: C&S should be drawn prior to initiation of therapy.
• Monitor carefully for signs of hypersensitivity response (see Appendix F), particularly in patients with history of allergies, especially to drugs.
• Monitor at-risk patients for S&S of superinfection (see Appendix F).
• Assess risk of toxic effects carefully; increases with renal and hepatic impairment.
• Supervise ambulation, since lightheadedness, dizziness, and vertigo occur frequently.

Patient & Family Education

• Avoid hazardous activities or those requiring alertness while taking minocycline.
• Use sunscreen when outdoors and otherwise protect yourself from direct sunlight since photosensitivity reaction may occur.
• Report vestibular adverse effects (e.g., dizziness), which usually occur during first week of therapy. Effects are reversible if drug is withdrawn.
• Report loose stools or diarrhea or other signs of superinfection promptly to physician.
• Use or add barrier contraceptive while taking this drug if using hormonal contraceptive.

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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