eMedicine Specialties > Neurology > Neurological Infections
Infectious Myositis: Treatment & Medication
Updated: Aug 12, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Medical Care
All medical care should be provided in conjunction with an infectious disease specialist and the primary care physician.
- HIV polymyositis: Corticosteroids remain the mainstay of treatment of polymyositis.
- Trichinosis
- Thiabendazole is effective if administered within 24 hours of infection. It has minimal effect in established infection.
- Optimal dosage has not been established.
- It can be combined with prednisone 40-60 mg/day in patients with severe pain and weakness.
- Trypanosomiasis
- Benznidazole is a trypanocidal drug that is quite effective in the acute phase of the illness.
- It reduces cardiac complications and parasitemia and has been found to be beneficial in the early chronic phase.
- Successful treatment is evinced by serological tests remaining negative for at least 1 year after conclusion of treatment.
- Viral myositis
- Treatment comprises bed rest, intravenous fluids, and symptomatic management with antipyretics and analgesics.
- Antiviral agents such as amantadine could be considered in adults.
- Tuberculous and toxoplasmal myositis, cysticercosis: Please refer to the following eMedicine articles: HIV-1 Associated Myopathies, Neurocysticercosis, and Neuroimaging in Neurocysticercosis.
- Pyomyositis
- Promptly administer systemic antibiotics. This could eliminate the need for surgical drainage in selected cases.
- The choice of antibiotic is determined by identification of the causative organism.
- Antibiotics initially are given intravenously until clinical improvement is noted, followed by oral antibiotics for a total course of 3 weeks (eg, cefazolin or ceftriaxone IV followed by cephalexin PO).
Surgical Care
Pyomyositis: During the suppurative phase, abscess aspiration under ultrasonic or CT guidance may be required. Surgical drainage is especially necessary for large abscesses.
Consultations
- Neurologist
- Infectious disease specialist
Medication
Treat the underlying cause of infectious myositis. Use appropriate antibiotics for pyomyositis. Prednisone may be effective to treat HIV-1–associated polymyositis.7
Corticosteroids
These agents decrease inflammatory reactions by reversing increased capillary permeability and suppressing PMN activity.
Prednisone (Deltasone, Orasone, Sterapred)
Can be used for HIV-1–associated polymyositis. Use in combination with thiabendazole for trichinosis.
Adult
40-60 mg PO qd
Pediatric
0.14-2 mg/kg PO qd
Estrogens may decrease clearance; when used with digoxin, may increase digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics
Documented hypersensitivity; viral infection; peptic ulcer disease; hepatic dysfunction; connective tissue infections; fungal or tubercular skin infections
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Take with meals to minimize gastric irritation; use with caution in peptic ulcer disease, diverticulitis, nonspecific ulcerative colitis, myasthenia gravis, osteoporosis, hypertension, and renal disease; avoid concomitant aspirin, NSAIDs, or alcohol; use cautiously in patients with HIV infection (can increase susceptibility to opportunistic infections)
Abrupt discontinuation may cause adrenal crisis; may cause hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections; can cause avascular necrosis of femoral head; use cautiously in ocular herpes simplex because of possible corneal perforation; may induce psychiatric symptoms or aggravate existing psychotic tendencies
Reduce dose gradually to minimize drug-induced secondary adrenocortical insufficiency
Anthelmintic
Parasite biochemical pathways are sufficiently different from those of the human host to allow selective interference by chemotherapeutic agents in relatively small doses.
Thiabendazole (Mintezol)
Treats trichinosis infections; inhibits helminth-specific mitochondrial fumarate reductase; alleviates symptoms of trichinosis during invasive phase. Little value in disease that spreads beyond lumen of intestines; absorption from GI tract is poor.
Adult
Optimal dosage not established; usual therapeutic regimen is 25 mg/kg PO for 2-4 consecutive d, taken after meals
Pediatric
25 mg/kg PO for 2-4 d; information on safety of thiabendazole in children <30 lb (13.6 kg) is limited
May elevate serum levels of theophylline, increasing toxicity (monitor serum levels and reduce dose prn)
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Closely monitor in hepatic or renal dysfunction; prior to initiating therapy, supportive therapy necessary for anemic, dehydrated, or malnourished patients; use in confirmed worm infestation, not prophylactically; may cause nausea, vomiting, and mild CNS depression
Mebendazole (Vermox)
May be useful in early stages of trichinosis. Causes worm death by selectively and irreversibly blocking uptake of glucose and other nutrients in susceptible adult intestine where helminths dwell.
Adult
200-400 mg PO tid for 3 d, followed by 400-500 mg PO tid for additional 10 d
Pediatric
<2 years: Not established
>2 years: Administer as in adults
Carbamazepine and phenytoin may decrease levels; cimetidine may increase levels
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Adjust dose in hepatic impairment; during prolonged treatment, perform periodic hepatic and hematopoietic monitoring; potential risk to fetus in pregnant women taking medication, especially in first trimester; unknown whether mebendazole excreted in human milk
Antibiotics
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Tetracycline (Sumycin)
For treatment of Lyme myositis. Treats gram-positive and gram-negative organisms as well as mycoplasmal, chlamydial, and rickettsial infections. Inhibits bacterial protein synthesis by binding with 30S and possibly 50S ribosomal subunit(s).
Adult
2 g/d PO divided in 2-4 equal doses for 1 mo
Pediatric
<8 years: Not recommended
>8 years: 25-50 mg/kg/d PO divided in 2-4 equal doses for 1 mo
Antacids containing aluminum, calcium, magnesium, iron, or bismuth subsalicylate decrease bioavailability; can decrease effects of oral contraceptives, causing breakthrough bleeding and increased risk of pregnancy; can increase hypoprothrombinemic effects of anticoagulants
Documented hypersensitivity; severe hepatic dysfunction
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Photosensitivity may occur with prolonged exposure to sunlight or tanning equipment; reduce dose in renal impairment; consider drug serum level determinations in prolonged therapy; if used during tooth development (last half of pregnancy through age 8 y), can cause permanent discoloration of teeth; also present in milk of lactating women; Fanconilike syndrome may occur with outdated tetracyclines; rarely causes myasthenic syndrome
Ceftriaxone (Rocephin)
Drug of choice for most neurologic manifestations of Lyme disease; third-generation cephalosporin with broad-spectrum, gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms. Arrests bacterial growth by binding to penicillin-binding proteins.
Adult
2 g/d IV for 2 wk
Pediatric
75-100 mg/kg/d IV for 2 wk
May increase ceftriaxone levels; ethacrynic acid, furosemide, and aminoglycosides may increase nephrotoxicity
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Dosage should not exceed 2 g/d in hepatic and renal dysfunction; patients with hepatic disease and malnutrition may require monitoring of PT; caution in patients with history of GI disease, especially colitis; discontinue in patients with signs or symptoms of gallbladder disease
Cefazolin (Ancef)
Can be used for treatment of pyomyositis. Semisynthetic cephalosporin effective against: S aureus (including penicillinase-producing strains), Staphylococcus epidermidis, group A beta-hemolytic streptococci, and other strains of streptococci.
Adult
500 mg to 1 g IV q6-8h
Pediatric
25-50 mg/kg/d (approximately 10-20 mg/lb/d) IV divided tid/qid
Probenecid may decrease renal tubular secretion, resulting in increased and more prolonged blood levels; false-positive reaction for urine glucose may occur with Benedict's solution, Fehling's solution, or Clinitest tablets but not with Clinistix or Tes-Tape
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Prolonged use may result in overgrowth of clostridia—close clinical observation of patient necessary; reduce dosage in patients with impaired renal function (may cause seizures when used in high doses in these patients); prescribe with caution in those with history of GI disease, particularly colitis; can render positive findings on direct and indirect antiglobulin (Coombs) tests
Cephalexin (Keflex, Biocef)
Indicated for treatment of infections by S aureus (including penicillinase-producing strains) and streptococci
Adult
500 mg PO q6h
Pediatric
Not established
False-positive reaction for urine glucose may occur with Benedict's solution, Fehling's solution, or Clinitest tablets but not with Clinistix or Tes-Tape
Documented hypersensitivity; penicillin sensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
May permit intestinal overgrowth of clostridia, leading to pseudomembranous colitis—careful clinical observation required; use with caution in patients with impaired renal function; prescribe with caution in those with history of GI disease, particularly colitis; can render positive findings on direct and indirect antiglobulin (Coombs) tests
Vancomycin (Vancocin)
For treatment of severe infections caused by methicillin-resistant (beta-lactam-resistant) staphylococci; and for treatment of staphylococcal infection in individuals allergic to penicillin or cephalosporins.
Adult
500 mg IV q6h or 1 g q12h; infuse each dose at no more than 10 mg/min or over 60 min
Pediatric
10 mg/kg per dose IV q6h
Infuse each dose over 60 min
When used concurrently with anesthetic agents can cause erythema and histaminelike flushing
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Rapid bolus administration may result in exaggerated hypotension and, rarely, cardiac arrest—avoid these complications by administering in dilute solution over at least 60 min; high doses can be ototoxic (transient or permanent); use with caution in patients with impaired renal function; prolonged use can lead to pseudomembranous colitis; requires periodic monitoring of neutrophil count (can cause reversible neutropenia)
More on Infectious Myositis |
| Overview: Infectious Myositis |
| Differential Diagnoses & Workup: Infectious Myositis |
 Treatment & Medication: Infectious Myositis |
| Follow-up: Infectious Myositis |
| Multimedia: Infectious Myositis |
| References |
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References
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Further Reading
Keywords
infectious myopathy, infectious polymyositis, pyomyositis, HIV infection
