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Toronto Notes 2019
Miscellaneous Lesions
Dermatology D45
Table 27. Common Oral Therapies (continued)
Drug Name
Doxycycline
Isotretinoin
(Accutane®)
Dosing Schedule
50 mg PO bid
0.5-1 mg/kg/d given OD to achieve a total dose of 120 mg/kg (20-24 wk)
Indications
Acne vulgaris Rosacea
Bullous pemphigoid
Severe nodular and/or inflammatory acne
Acne conglobata Recalcitrant acne Widespread comedonal acne
Onychomycosis
Tinea corporis, cruris, pedis, versicolor, capitis
Onchocerciasis (USA only) Not licensed for use in Canada Also effective for: scabies
Psoriasis
AD
Lymphomatoid papulosis May also be effective in: cutaneous sarcoidosis
Hormonal acne (chin, jawline) Acne associated with polycystic ovarian syndrome or other endocrine abnormalities
Hormonal acne (chin, jawline) Acne with endocrine abnormality
Onychomycosis
Tinea corporis, cruris, pedis, capitis
Acne vulgaris Rosacea
Bullous pemphigoid
Comments
Contraindications
Pregnancy, hepatic impairment, drug hypersensitivity Taking acitretin, isotretinoin, or penicillin antibiotic Oral typhoid vaccine
Monitoring strategies
Baseline lipid profile and LFTs before treatment, β-hCG
Contraindications
Teratogenic – in sexually active females, 2 forms of reliable contraception necessary Generally regarded as unsafe in lactation
Side effects
Decreased night vision, decreased tolerance to contact lenses, dry mucous membranes May transiently exacerbate acne, dry skin
Depression, myalgia
Drug interactions
Caution if used at the same time as tetracyclinefamily antibiotics – both may cause pseudotumour cerebri
Discontinue vitamin A supplements
Drug may be discontinued at 16-20 wk when nodule count has dropped by >70%; a second course may be initiated after 2 mo prn
Refractory cases may require >3 courses
Contraindications
CHF
Side effects
Serious hepatotoxicity
Drug Interactions
Inhibits CYP3A4
Increases concentration of some drugs metabolized by this enzyme (i.e. statins, diabetic drugs)
Give capsules with food, capsules must be swallowed whole
No significant serious side effects Efficacious
Monitoring strategies
Baseline renal, liver, and hematological studies
Contraindications
Pregnancy, lactation, alcohol abuse, liver dysfunction, immunodeficiency syndrome, blood dyscrasias, hypersensitivity to drug
Restricted to severe, recalcitrant or disabling psoriasis not adequately responsive to other forms of therapy
May be combined with cyclosporine to allow lower doses of both drugs
All combined OCPs are helpful in acne but those listed on the left have undergone RCTs Contraindications
Smoking, HTN, migraines with aura, pregnancy
Routine gynecological health maintenance should be up to date
Contraindications
Pregnancy
Side effects
Menstrual irregularities at higher doses if not on OCPs Breast tenderness, mild diuresis common
Risk of hyperkalemia – counsel patients to reduce intake of potassium rich foods such as bananas
Contraindications
Pregnancy, chronic or active liver disease
Drug interactions
Potent inhibitor of CYP2D6; use with caution when also taking β-blockers, certain anti- arrhythmic agents, MAOI type B, and/or antipsychotics
Drug concentrates rapidly in skin, hair, and nails at levels associated with fungicidal activity
Contraindications
Severe renal or hepatic dysfunction
Itraconazole
(Sporanox®)
Ivermectin
(Mectizan®, Stromectol®)
Methotrexate
(Trexall®)
OCPs
(TriCyclen®, Diane 35®, Alesse®)
Spironolactone
Terbinafine
(Lamisil®)
Tetracycline
100-400 mg PO OD, depending on infection
Tinea corporis/cruris/versicolor: 200 mg PO OD x 7 d
Tinea pedis: 200 mg PO bid x 7 d Toenails: 200 mg PO bid x 7 d once per month, repeated 3x Fingernail involvement only: 200 mg bid PO x 7 d once per month, repeated 2x
200-250 μg/kg PO qweekly x 2 Take once as directed; repeat one wk later
10-25 mg qwk, PO, IM, or IV Max: 30 mg/wk
To minimize side effects, administer with folic acid supplementation:
1-5 mg OD 1 pill PO OD
50-100 mg PO OD alone or with OCPs
250 mg PO OD x 2 wk Fingernails x 6 wk Toenails x 12 wk
Confirm diagnosis prior to treatment
250-500 mg PO bid to tid Taken 1 h before or 2 h after a meal