Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Antimicrobial therapy is essential (though most cases of acute Q fever improve without intervention) to minimize risk of chronic Q fever. Prolonged antibiotic therapy is critical in managing chronic Q fever, although exact antibiotics recommended for use are in a state of flux. Consultation with an infectious disease specialist is recommended to assist in the choice of antibiotics. The best studied are combinations of doxycycline plus an additional antibiotic (eg, fluoroquinolone, rifampin, trimethoprim-sulfamethoxazole).
Patients with Q fever who are misdiagnosed with legionellosis have responded well to intravenous (IV) erythromycin, which probably is effective for pregnant patients, although no controlled trials have been performed. Some investigators use lysosomal alkalinizing agents (eg, hydroxychloroquine) for patients with chronic Q fever to increase the effectiveness of antibiotics.
Treatment of pregnant women is complicated. Infectious disease and obstetric consultations should be sought.
Antibiotics, Other
Class Summary
Antibiotic drugs are used to provide in vivo or in vitro activity against Coxiella burnetii infections. However, empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the clinical setting.
Doxycycline is the drug of choice (DOC) in Q fever; however, in a series of pregnant patients with Q fever, trimethoprim-sulfamethoxazole (TMP-SMZ) was used with some success. [45] In the chronic setting, the addition of chloroquine to doxycycline may improve outcomes, although data are sparse.
Doxycycline (Vibramycin, Doryx, Monodox)
Doxycycline is the first-line agent for both acute and chronic Q diseases. This agent is a bacteriostatic drug that interferes with bacterial protein and cell-wall synthesis during active multiplication by binding to 30S ribosome. For severe cases, administer intravenously (IV); for outpatients, oral administration (PO) is preferred.
Ofloxacin
Ofloxacin is an alternative antibiotic to doxycycline in acute Q fever. This quinolone agent is a derivative of pyridine carboxylic acid with broad-spectrum bactericidal effect. Quinolones are effective in treating Q fever alone or when combined with doxycycline; consultation with an infectious disease specialist is recommended before its use.
Rifampin (Rifadin)
Rifampin is used to treat all forms of tuberculosis in combination with at least one other antituberculous drug. This agent inhibits RNA synthesis in bacteria by binding to the beta subunit of DNA-dependent RNA polymerase, which in turn blocks RNA transcription. Cross-resistance has only been shown with other rifamycins; combination therapy with doxycycline should be continued for chronic Q fever for at least 18 months.
Sulfamethoxazole and Trimethoprim (Bactrim, Bactrim DS, Septra DS)
Sulfamethoxazole and trimethoprim inhibits bacterial growth by inhibiting the synthesis of dihydrofolic acid. This would be a drug to use in pregnant women after consultation with the patient's obstetrician and an infectious disease specialist.
Azithromycin (Zithromax, Zmax)
Zithromax treats mild to moderate microbial infections by binding to the 50S ribosomal subunit of susceptible microorganisms and blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Nucleic acid synthesis, however, is not affected.
This agent concentrates in phagocytes and fibroblasts, as demonstrated by in vitro incubation techniques. In vivo studies suggest that the concentration in phagocytes may contribute to drug distribution to inflamed tissues. Plasma concentrations are very low, but tissue concentrations are much higher, giving azithromycin value in treating intracellular organisms. This drug has a long tissue half-life.
Tetracycline
Tetracycline treats susceptible both gram-positive and gram-negative bacterial infections, as well as infections caused by species of Mycoplasma, Chlamydia, and Rickettsia. This agent inhibits bacterial protein synthesis by binding with the 30S and possibly 50S ribosomal subunits of susceptible bacteria.
Chloramphenicol
Chloramphenicol is used in patients who do not tolerate tetracycline. This agent binds to the 50S bacterial ribosomal subunits and inhibits bacterial growth by inhibiting protein synthesis. Chloramphenicol is effective against gram-negative and gram-positive bacteria. In severe cases, administer intravenously (IV); for outpatients, administer orally (PO).
Ciprofloxacin (Cipro)
Ciprofloxacin is a quinolone that is effective in treating Q fever alone or when combined with doxycycline. Consultation with an infectious disease specialist is recommended before its use.
Antimalarials
Class Summary
Antimalarial agents are used for their alkalinizing action within the phagolysosomal compartment of monocytes, where C burnetii resides.
Hydroxychloroquine (Plaquenil)
Hydroxychloroquine is used in chronic Q fever with doxycycline, which is more effective. This agent results in fewer relapses than that with doxycycline and ofloxacin, and its treatment duration can be shortened. Hydroxychloroquine sulfate 200 mg is equivalent to 155 mg hydroxychloroquine base and 250 mg chloroquine phosphate.
Analgesics, Other
Class Summary
Treatment of Q fever is symptomatic and supportive. Bed rest and mild analgesic-antipyretic therapy often help to relieve the lethargy, malaise, and fever associated with this disease.
Ibuprofen (Advil, Motrin, Caldolor, I-Prin)
Ibuprofen is usually the drug of choice (DOC) to treat mild to moderate headache unless contraindicated. This agent is also one of the few nonsteroidal anti-inflammatory drugs (NSAIDs) that is indicated for reduction of fever.
Acetaminophen (Tylenol, Feverall, Mapap, Aspirin Free Anacin)
Acetaminophen is the drug of choice (DOC) for treatment of pain in documented hypersensitivity to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) and in gastrointestinal (GI) disease or with oral (PO) anticoagulants. This agent reduces fever by directly acting on hypothalamic heat-regulating centers, increasing the dissipation of body heat by vasodilation and sweating.
Salicylates
Class Summary
Acetylsalicylic agents are effective in alleviating headaches, possibly because of their inhibition of prostaglandin synthesis.
Aspirin (Anacin, Ecotrin, Bayer Aspirin Extra Strength, Bufferin)
Aspirin is used to treat mild to moderate pain and headache. This agent blocks prostaglandin synthetase action, which in turn inhibits prostaglandin synthesis and prevents formation of platelet-aggregating thromboxane A2. Aspirin enhances dissipation of heat by vasodilating peripheral vessels, causing a decrease in body temperature, as well as acts on the hypothalamus heat-regulating center to reduce fever.
Antitussives
Class Summary
Treatment of Q fever is symptomatic and supportive. Antitussives help to relieve the coughing associated with pneumonia, which is among the most common presenting symptoms. Few data on the effectiveness of expectorants outside the test tube have been reported. The prototype antitussive, codeine, was successfully used in models of chronic and induced cough, but clinical data for upper respiratory infections are limited. Existing data report the effectiveness of codeine to be somewhat equal to that of guaifenesin, dextromethorphan, or even placebo.
Dextromethorphan/guaifenesin (Mucinex DM, Robafen DM, Double Tussin DM)
Dextromethorphan is used for treatment of minor cough resulting from bronchial and throat irritation.
Benzonatate (Tessalon, Zonatuss)
Benzonatate is used for the symptomatic relief of cough. This agent suppresses cough by anesthetizing stretch receptors located in the respiratory passages, lungs, and pleura by dampening activity and reducing cough reflex.
Codeine/guaifenesin (Tussin-C, Allfen CD, ExeClear-C)
The combination of codeine and guaifenesin is used to treat minor cough resulting from bronchial and throat irritation.
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A: Chest radiograph with normal findings. B: Chest radiograph demonstrating Q fever pneumonia.
