Pruritus drug therapy

A mild jaundice, typically occurring early in therapy, may be seen in some patients receiving chlorpromazine. Pruritus is rare. The reaction probably is a manifestation of hypersensitivity, because eosinophilia and eosinophilic infiltration of the liver occur. For uninterrupted drug therapy in a patient with neuroleptic-induced jaundice, it probably is safest to use low doses of a potent, dissimilar agent. Hepatic dysfunction with other antipsychotic agents is uncommon. Clozapine can cause potentially severe ileus and sialorrhea. 

Select azole antifungals (e.g., itraconazole, voriconazole, and posaconazole) and the echinocandins are available for IA treatment. For initial therapy of IA, voriconazole had higher response and survival rates than c-AMB.102 An advantage of voriconazole is its 96% oral bioavailability, making use of this oral drug an attractive and less expensive alternative. The dose of voriconazole was 6 mg/kg IV every 12 hours for two doses, followed by 4 mg/kg IV every 12 hours for at least 7 days, at which time oral voriconazole 200 mg every 12 hours could be administered. Common toxicities reported with voriconazole include infusion-related, transient visual disturbances (i.e., blurred vision, altered color perception, photophobia, and visual hallucinations), skin reactions (i.e., rash, pruritus, and photosensitivity), elevations in hepatic transaminases and alkaline phosphatase, nausea, and headache.102 In addition, voriconazole increases the serum concentrations of medications cleared by cytochrome P-450 2C9, 2C19, and 3A4 (e.g., cyclophosphamide and calcineurin inhibitors) concomitant voriconazole-sirolimus should be avoided.103... 

Calcium gluconate - To decrease capillary permeability in allergic conditions, nonthrombocytopenic purpura and exudative dermatoses such as dermatitis herpetiformis for pruritus of eruptions caused by certain drugs in hyperkalemia, calcium gluconate may aid in antagonizing the cardiac toxicity, provided the patient is not receiving digitalis therapy. 

Hypersensitivity reactions Allergic reactions occur in approximately 33% of patients. They are more common at the start of treatment, and occur as generalized rashes or drug fever. Discontinue treatment and reinstitute at a low dosage such as 250 mg/day, with gradual increases. Administering prednisolone 20 mg/day for the first few weeks of penicillamine therapy reduces the severity of these reactions. Antihistamines may control pruritus. 

CBZ can cause morbilliform rashes which may also produce intense pruritus, usually within the first 6 weeks of therapy. Approximately 10% of patients develop a rash but do not usually require cessation of the drug. The involvement of the mucous membranes, fever, or other constitutional symptoms may indicate the development of Stevens-Johnson or Lydeli syndromes. These rashes are rare but potentially life-threatening, occurring in less than one out of 50,000 patients. Their appearance requires immediate cessation of CBZ and prompt medical intervention. 

The most common reaction to antithyroid drugs is a benign skin rash or pruritus without rash. Although such a reaction is usually not serious and can even disappear during continuous treatment, it nevertheless indicates an allergic reaction and requires withdrawal of therapy. Thiouracil can then be replaced by thioimida-zoles, but allergy to both products can occasionally occur. 

Skin problems can be persistent in a proportion of patients, variously estimated at 10-59%, and this can severely limit adherence to therapy. The skin reaction can be ameliorated by concomitant use of non-steroidal anti-inflammatory drugs such as aspirin and indometacin (SEDA-15, 412). Transient exanthems, pruritus, and sometimes wheals are seen, as well a uniform dryness and scaling of the epidermis, brown pigmentation, and even on occasion an acanthosis nigricans-like dermatosis (15). Persistent rashes can also occur. Doses in excess of 5 g/day are routinely associated with skin manifestations and can on occasion cause liver damage, gout and ulcer formation. These reactions can be associated with nicotinic acid rather than nicotinamide, which is sometimes recommended as an alternative (37). Increased hair loss has been described. 

Question A.22 The hypersensitivity reaction was not serious enough to warrant stronger pharmacologic therapy, but the patient requests some remedy to stop the pruritus (itching). Which of the following drugs should be recommended ... 

In the early years of its use, vancomycin developed a reputation as being a relatively toxic drug. The most important side effects associated with vancomycin therapy are an anaphylactoid reaction referred to as the red man syndrome or the red neck syndrome, ototoxicity, and nephrotoxicity. Typically, the red man syndrome develops upon rapid infusion of vancomycin and consists of pruritus, a rash involving the face. 

The most frequent adverse event associated with nevirapine is rash, which occurs in approximately 16% of patients. Mild macular or papular eruptions commonly involve the trunk, face, and extremities and generally occur within the first 6 weeks of therapy. Pruritus is also common. In the majority of patients, the rash resolves with continued administration of drug. Up to 7% of patients discontinue therapy owing to rash, and administration glucocorticoids may cause a more severe rash. Life-threatening Stevens-Johnson syndrome is rare but occurs in up to 0 3% of recipients. 

Constipation, headache, pruritus, mild nausea, nervousness, and peripheral edema are most common. More serious effects, such as hypotension, bradycardia, and asystole may also result, particularly if the drug is administered in combined therapy with a P-blocker. 

Doses of chloroquine used for oral therapy of the acute malarial attack may cause GI upset, headache, visual disturbances, and urticaria. Pruritus also occurs, most commonly among dark-skinned persons. Prolonged medication with suppressive doses occasionally causes side effects such as headache, blurring of vision, diplopia, confusion, convulsions, lichenoid skin eruptions, bleaching of hair, widening of the QRS interval, and T-wave abnormalities. These complications usually disappear soon rffter the drug is withheld. Rare instances of hemolysis and blood dyscrasias have been reported. Chloroquine may cause discoloration of nail beds and mucous membranes. 

The sulfonamides are associated with a number of skin and mucous membrane manifestations attributed to sensitization to sulfonamide, including various rashes, erythema nodosum, erythema multiforme of the Stevens-Johnson type, Behget s syndrome, exfoliative dermatitis, and photosensitivity. These hypersensitivity reactions usually occur after the first week of therapy but may appear earlier in previously sensitized individuals. Fever, malaise, and pruritus frequently are present simultaneously. The incidence of untoward dermal effects is -2% with sulfisoxazole, although a higher frequency is seen in patients with AIDS. A syndrome similar to serum sickness may appear after several days of sulfonamide therapy. Drug fever occurs in -3% of patients treated with sulfisoxazole. 

Fewer than 2% of patients who received daily doses of 15 mg/kg of ethambutol had adverse reactions, including diminished visual acuity, rash, drug fever, pruritus, joint pain, GI upset, malaise, headache, dizziness, confusion, disorientation, and hallucinations. Numbness and tingling of the fingers owing to peripheral neuritis are infrequent. Anaphylaxis and leukopenia are rare. Therapy with ethambutol increases urate concentration in the blood in -50% of patients, owing to decreased renal excretion of uric acid. 

Allergic reactions (exanthemas, photosensitization, pruritus, eosinophilia, fever, reversible leukopenia, and occasionally hemolytic anemia) are described after administration of nalidixic acid and pipemidic acid. Excessive exposure to sunlight and ultraviolet light should be avoided during therapy with these drugs (Baes 1968 Birkett et al, 1969 Ramsay 1973 Brehm and Korting 1970 Louis et al. 1973 Burry 1974 Ramsay and Obreskova 1974 Boisvert and Barbeau 1981). 

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