eMedicine Specialties > Pulmonology > Occupational Lung Diseases
Silicosis: Treatment & Medication
Updated: Apr 16, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
- Prevent further exposure to silica dust.
- Strongly advise patients to quit smoking and provide help in smoking cessation efforts.
- Immunize patients against influenza and pneumococcal pneumonia.
- No specific therapy for silicosis cures or alters the course of the disease.
- Corticosteroids may be of benefit in acute silicosis.3 In chronic silicosis, they are unlikely to be of benefit, although pulmonary function improvement was noted in one study.4
- Selectively in patients with very advanced disease without other comorbid conditions, lung transplantation may be an option.
- Experimental (unproven) approaches to treatment include whole-lung lavage, aluminum inhalation, and parenteral administration of polyvinyl pyridine N-oxide.
- Latent tuberculosis infection (ie, positive tuberculin skin test result without active disease) should be treated with isoniazid (see Medication). A 10-mm induration is considered a positive test result in this population.
- Active tuberculosis (ie, Mycobacterium tuberculosis identified in smear or culture) should be treated with appropriate multiple drugs (see Medication) according to the most recently established guidelines.
- Complications (eg, airflow obstruction, cor pulmonale, respiratory failure), should they occur, should be treated appropriately.
Surgical Care
Selectively in patients with very advanced silicosis and without other significant comorbid conditions, lung transplantation should be considered.
Consultations
Consulting a pulmonologist is appropriate for evaluation of lung nodules, pulmonary function assessment, and disability evaluation, as well as treatment of mycobacterial disease and complications of advanced silicosis.
Diet
No dietary restrictions are necessary.
Activity
No restrictions on activity are necessary.
Medication
Latent tuberculosis: Isoniazid for 9 months, daily or intermittently (twice weekly directly observed treatment [DOT]), is the DOC.
Active tuberculosis: Several multidrug regimens are available using more drugs daily and reducing the number of drugs and converting to an intermittent DOT schedule. Treatment duration is 6-9 months and at least 3 months beyond negative culture results. Drugs used in treatment include isoniazid, rifampin, pyrazinamide, streptomycin, and ethambutol.
Antitubercular agents
Active against susceptible strains of M tuberculosis.
Isoniazid (Nydrazid)
Best combination of effectiveness, low cost, and minor adverse effects. First-line drug unless known resistance or another contraindication is present.
Adult
5 mg/kg PO qd; not to exceed 300 mg qd
Alternatively, 15 mg/kg PO 2 times/wk; not to exceed 900 mg/dose
Pediatric
10-20 mg/kg PO qd; not to exceed 300 mg qd
Alternatively, 20-40 mg/kg 2 times/wk; not to exceed 900 mg/dose
Higher incidence of isoniazid-related hepatitis can occur with alcohol ingestion on daily basis; aluminum salts may decrease isoniazid serum levels (administer 1-2 h before patient takes aluminum salts); may increase anticoagulant effects with coadministration; may inhibit metabolic clearance of benzodiazepines; carbamazepine toxicity or isoniazid hepatotoxicity may result from concurrent use (monitor carbamazepine concentrations and liver function); coadministration with cycloserine may increase CNS adverse effects (eg, dizziness); acute behavioral and coordination changes may occur with coadministration of disulfiram; coadministration with rifampin after halothane anesthesia may result in hepatotoxicity and hepatic encephalopathy; may inhibit hepatic microsomal enzymes and increase toxicity of hydantoin
Documented hypersensitivity; previous isoniazid-associated hepatic injury or other severe adverse reactions
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
Monitor patients with active chronic liver disease or severe renal dysfunction; periodic ophthalmologic examinations during therapy are recommended even when visual symptoms do not occur; associated with peripheral neuropathy
Rifampin (Rifadin)
For use in combination with at least 1 other antituberculous drug. Inhibits DNA-dependent bacterial, but not mammalian, RNA polymerase. Cross-resistance may occur. Treat for 6-9 mo and at least until 3 mo beyond negative culture results.
Adult
10 mg/kg PO/IV qd; not to exceed 600 mg qd
Alternatively, 10 mg/kg PO/IV 2 times/wk; not to exceed 600 mg qd
Pediatric
10-20 mg/kg PO/IV; not to exceed 600 mg qd
Alternatively, 10-20 mg/kg PO/IV 2 times/wk; not to exceed 600 mg qd
Induces microsomal enzymes, which may decrease effects of acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta-blockers, chloramphenicol, oral contraceptives, corticosteroids, mexiletine, cyclosporine, digitoxin, disopyramide, estrogens, hydantoins, methadone, clofibrate, quinidine, dapsone, tazobactam, sulfonylureas, theophyllines, tocainide, and digoxin; blood pressure may increase with coadministration of enalapril; coadministration with isoniazid may result in higher rate of hepatotoxicity than with either agent alone (discontinue one or both agents if alterations in LFTs occur)
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
Obtain CBCs and baseline clinical chemistries prior to and throughout therapy; in patients with liver disease, weigh benefits against risk of further liver damage; interruption of therapy and high-dose intermittent therapy are associated with thrombocytopenia that is reversible if therapy is discontinued as soon as purpura occurs; if treatment is continued or resumed after appearance of purpura, cerebral hemorrhage or death may occur; orange discoloration of urine and secretions, nausea, vomiting, febrile reaction, and hepatitis have occurred
Pyrazinamide (PZA)
Pyrazine analog of nicotinamide that may be bacteriostatic or bactericidal against M tuberculosis, depending on concentration of drug attained at site of infection. Mechanism of action is unknown. This drug should be used only in combination with other antituberculous drugs.
Adult
15-30 mg/kg PO qd; not to exceed 2 g/d; alternatively, 50-70 mg/kg PO 2 times/wk; not to exceed 4 g/d
Pediatric
Administer as in adults
None reported
Documented hypersensitivity; severe hepatic damage; acute gout
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
Clinical monitoring at week 2, 4, and 8 and blood tests as warranted; use only in combination with other effective antituberculous agents; inhibits renal excretion of urates; may result in hyperuricemia (usually asymptomatic); perform baseline serum uric acid determinations; discontinue if signs of hyperuricemia with acute gouty arthritis appear; perform baseline LFTs (closely monitor in patients with liver disease); discontinue if signs of hepatocellular damage appear; caution in patients with history of diabetes mellitus; associated with rash and GI distress; teratogenic potential is undetermined
Streptomycin
For treatment of susceptible mycobacterial infections. Use in combination with other antituberculous drugs (eg, isoniazid, ethambutol, rifampin).
Adult
15 mg/kg/d IM qd; not to exceed 1 g qd; reduce dose in patient aged >60 y; not to exceed 750 mg qd
Alternatively, 25-30 mg/kg/d IM 2 times/wk; not to exceed 1.5 g/d
Pediatric
40 mg/kg/d IM; not to exceed 1 g/d
Alternatively, 25-30 mg/kg/d IM 2 times/wk; not to exceed 1.5 g/d
Nephrotoxicity may be increased with aminoglycosides, cephalosporins, penicillins, amphotericin B, and loop diuretics
Documented hypersensitivity; non–dialysis-dependent renal insufficiency
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Clinically monitor and check for acuity of hearing and renal function tests; narrow therapeutic index; not intended for long-term therapy; caution in patients with renal failure who are not on dialysis; caution in patients with myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; associated with ototoxicity; ototoxic to fetus
Ethambutol (Myambutol)
Diffuses into actively growing mycobacterial cells (eg, tubercle bacilli). Impairs cell metabolism by inhibiting synthesis of one or more metabolites, which in turn causes cell death. No cross-resistance demonstrated. This drug should be used only in combination with other antituberculous drugs.
Adult
15-25 mg/kg PO qd; not to exceed 2.5 g/d
Alternatively, 50 mg/kg PO 2 times/wk
Pediatric
<13 years: Not recommended
>13 years: Administer as in adults
Aluminum salts may delay and reduce absorption (administer several h before or after ethambutol dose)
Documented hypersensitivity; optic neuritis (unless clinically indicated)
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Reduce dose in patients impaired renal function; associated with optic neuritis and rash; monitor color discrimination (ie, red-green) and visual acuity; treatment should not be deferred during pregnancy; preferred drugs in initial treatment are isoniazid, rifampin, and ethambutol
More on Silicosis |
| Overview: Silicosis |
| Differential Diagnoses & Workup: Silicosis |
 Treatment & Medication: Silicosis |
| Follow-up: Silicosis |
| References |
| « Previous Page | Next Page » |
References
Caplan A, Payne RB, Withley JL. A broadened concept of Caplan's syndrome related to rheumatoid factors. Thorax. 1962;17:205-209.
Centers for Disease Control and Prevention. Silicosis in dental laboratory technicians--five states, 1994-2000. MMWR Morb Mortal Wkly Rep. Mar 12 2004;53(9):195-7. [Medline].
Goodman GB, Kaplan PD, Stachura I, Castranova V, Pailes WH, Lapp NL. Acute silicosis responding to corticosteroid therapy. Chest. Feb 1992;101(2):366-70. [Medline].
Sharma SK, Pande JN, Verma K. Effect of prednisolone treatment in chronic silicosis. Am Rev Respir Dis. Apr 1991;143(4 Pt 1):814-21. [Medline].
Rosenman KD, Moore-Fuller M, Reilly MJ. Connective tissue disease and silicosis. Am J Ind Med. Apr 1999;35(4):375-81. [Medline].
Mulloy KB. Silica exposure and systemic vasculitis. Environ Health Perspect. Dec 2003;111(16):1933-8. [Medline].
American Thoracic Society. Targeted tuberculin testing and treatment of latent tuberculosis infection. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. This is a Joint Statement of the American Thoracic Society (ATS) and the Centers for Disease Control and Prevention (CDC). This statement was endorsed by the Council of the Infectious Diseases Society of America. (IDSA), September 1999, and the sections of this statement. Am J Respir Crit Care Med. Apr 2000;161(4 Pt 2):S221-47. [Medline].
Arakawa H, Honma K, Saito Y, Shida H, Morikubo H, Suganuma N. Pleural disease in silicosis: pleural thickening, effusion, and invagination. Radiology. Aug 2005;236(2):685-93. [Medline].
Attfield MD, Costello J. Quantitative exposure-response for silica dust and lung cancer in Vermont granite workers. Am J Ind Med. Feb 2004;45(2):129-38. [Medline].
Banks DE, Balaan M, Wang ML. Silicosis in the 1990s, revisited. Chest. Apr 1997;111(4):837-8.
Corbett EL, Churchyard GJ, Clayton T, Herselman P, Williams B, Hayes R. Risk factors for pulmonary mycobacterial disease in South African gold miners. A case-control study. Am J Respir Crit Care Med. Jan 1999;159(1):94-9. [Medline].
Corbett EL, Murray J, Churchyard GJ, Herselman PC, Clayton TC, De Cock KM. Use of miniradiographs to detect silicosis. Comparison of radiological with autopsy findings. Am J Respir Crit Care Med. Dec 1999;160(6):2012-7. [Medline].
Gamble JF, Hessel PA, Nicolich M. Relationship between silicosis and lung function. Scand J Work Environ Health. Feb 2004;30(1):5-20.
Ghio AJ, Kennedy TP, Schapira RM, Crumbliss AL, Hoidal JR. Hypothesis: is lung disease after silicate inhalation caused by oxidant generation?. Lancet. Oct 20 1990;336(8721):967-9. [Medline].
Graham WGB. Quartz and silicosis. In: Banks D, Parker J, eds. Occupational Lung Disease: An International Perspective. New York, NY: Chapman & Hall Medical; 1998:191-212.
Hertzberg VS, Rosenman KD, Reilly MJ, Rice CH. Effect of occupational silica exposure on pulmonary function. Chest. Aug 2002;122(2):721-8. [Medline].
Lapp NL. Pulmonary function and disability. In: Banks D, Parker J, eds. Occupational Lung Disease: An International Perspective. 1998. New York, NY: Chapman & Hall Medical; 1998:17-34.
McDonald JC, McDonald AD, Hughes JM, Rando RJ, Weill H. Mortality from lung and kidney disease in a cohort of North American industrial sand workers: an update. Ann Occup Hyg. Jul 2005;49(5):367-73. [Medline].
National Archives and Records Administration. United States code of federal regulations. 1910.1000. Office of the Federal Register, National Archives and Records Administration; 1994.
Rimal B, Greenberg AK, Rom WN. Basic pathogenetic mechanisms in silicosis: current understanding. Curr Opin Pulm Med. Mar 2005;11(2):169-73.
Valiante DJ, Schill DP, Rosenman KD, Socie E. Highway repair: a new silicosis threat. Am J Public Health. May 2004;94(5):876-80. [Medline].
Wagner GR. Screening and surveillance of workers exposed to mineral dusts. Geneva, World Health Organization. 1996.
Further Reading
Keywords
silicosis, pneumoconiosis, pneumoconioses, fibronodular lung disease, work-related illness, mining illness, mining, tunneling, quarrying, drilling, crushing stone, chipping, grinding, sandblasting, cement manufacturing, building construction, occupational hazard, cutting bricks, manufacturing bricks, silica dust, silica exposure
