E ffective treatment of acne and rosacea sometimes requires the use of systemic antibiotic therapy. As acne and rosacea are chronic disorders, oral antibiotic treatment is often continued for several months or longer in order to maintain control of the disease and reduce the frequency and severity of exacerbations. Fortunately, the oral antibiotics that are most commonly prescribed (e.g. tetracyclines, macrolides) are associated with excellent efficacy and safety track records over several decades of use. Once it’s been established that a patient has responded to a given oral agent and has not experienced any adverse effects, therapy is often continued with a high level of comfort. It’s important, however, for the clinician to be aware of potential adverse reactions and clinically significant drug interactions associated with commonly prescribed therapies. The following case, shared with me by a colleague who encountered an uncomfortable experience, represents a significant drug interaction that occurred in a patient treated for acne with a macrolide antibiotic agent. CASE HISTORY A 32-year-old female presented with diffuse facial acne vulgaris that was partially responsive to a variety of prescribed combination topical acne regimens used for several months. Although the superficial acne lesions responded well to topical therapy, the major component of bothersome refractory acne was deeper inflammatory lesions. The use of oral contraceptive therapy (Ortho Tri-Cyclen) over 6 months resulted in minimal therapeutic benefit. Past medical history was significant for allergic rhinitis treated with fexofenadine (Allegra) 60 mg twice daily and an intermittent facial pain (tic) disorder treated with phenytoin (Dilantin) 300 mg twice daily. Oral tetracycline 500 mg twice daily was added to the treatment regimen with excellent results noted at an 8-week follow-up. The patient was maintained on tetracycline therapy thereafter, along with her topical regimen, which included sulfacetamide 10%/sulfur 5% cleanser (Plexion Cleanser) used twice daily, benzoyl peroxide 3% gel (Triaz) applied in the morning and tazarotene 0.05% cream (Tazorac) applied nightly. Once disease control was established for the first 3 to 4 months, the patient was followed every 4 to 6 months thereafter. Attempts to discontinue oral therapy over the next several months were unsuccessful, resulting in long term use of oral tetracycline. Approximately 3 months after her last visit, the patient contacted the dermatology office complaining that tetracycline was difficult to use as she sunburned more easily despite applying sunscreen. The dermatology nurse reported this to the dermatologist who changed the patient to oral erythromycin 500 mg twice daily to be administered with food, with instructions to follow up in 6 to 8 weeks. Complications Six days later, the dermatologist was notified by a local emergency room physician that the patient presented with drowsiness, dizziness, ataxia and blurred vision and was admitted to the hospital for observation. Laboratory testing revealed carbamazepine intoxication, related to the co-administration of oral erythromycin, with a serum carbamazepine (Tegretol) level of 21 µg/ml (the therapeutic range is 2 µg/ml to 10 µg/ml). On checking the patient’s record, the dermatologist noted that there was no indication that carbamazepine was used by the patient as it didn’t appear on the medication list that was filled out on the “patient history form” at her first visit. However, after her most recent dermatology visit, and before the telephone order to discontinue tetracycline and start oral erythromycin, the patient’s neurologist changed her therapy for facial pain from phenytoin to carbamazepine. A carbamazepine dosage of 800 mg per day had resulted in clinical improvement, with maintenance of a therapeutic serum level ranging from 6 µg/ml to 8 µg/ml. When she discontinued the oral erythromycin, her symptoms of carbamazepine intoxication resolved within 7 days without any further adverse sequelae. Discussion It’s easy to appreciate how this situation may occur. Overall, erythromycin is a very safe medication. The dermatologist didn’t perceive a risk of prescribing erythromycin to an established patient based on a telephone conversation, knowing that this patient was consistently compliant with follow-up recommendations. Unfortunately, the dermatologist wasn’t aware of the complete picture. It’s important that a patient’s medical history and current medication list be updated before prescribing new therapies. This represents an important issue for physician awareness and education of any office staff who interact with patients and participate in the “chain” of clinical decisions, including telephone interactions.
This Expert Shares Problem-Solving Insights about a Challenging Acne Case.
E ffective treatment of acne and rosacea sometimes requires the use of systemic antibiotic therapy. As acne and rosacea are chronic disorders, oral antibiotic treatment is often continued for several months or longer in order to maintain control of the disease and reduce the frequency and severity of exacerbations. Fortunately, the oral antibiotics that are most commonly prescribed (e.g. tetracyclines, macrolides) are associated with excellent efficacy and safety track records over several decades of use. Once it’s been established that a patient has responded to a given oral agent and has not experienced any adverse effects, therapy is often continued with a high level of comfort. It’s important, however, for the clinician to be aware of potential adverse reactions and clinically significant drug interactions associated with commonly prescribed therapies. The following case, shared with me by a colleague who encountered an uncomfortable experience, represents a significant drug interaction that occurred in a patient treated for acne with a macrolide antibiotic agent. CASE HISTORY A 32-year-old female presented with diffuse facial acne vulgaris that was partially responsive to a variety of prescribed combination topical acne regimens used for several months. Although the superficial acne lesions responded well to topical therapy, the major component of bothersome refractory acne was deeper inflammatory lesions. The use of oral contraceptive therapy (Ortho Tri-Cyclen) over 6 months resulted in minimal therapeutic benefit. Past medical history was significant for allergic rhinitis treated with fexofenadine (Allegra) 60 mg twice daily and an intermittent facial pain (tic) disorder treated with phenytoin (Dilantin) 300 mg twice daily. Oral tetracycline 500 mg twice daily was added to the treatment regimen with excellent results noted at an 8-week follow-up. The patient was maintained on tetracycline therapy thereafter, along with her topical regimen, which included sulfacetamide 10%/sulfur 5% cleanser (Plexion Cleanser) used twice daily, benzoyl peroxide 3% gel (Triaz) applied in the morning and tazarotene 0.05% cream (Tazorac) applied nightly. Once disease control was established for the first 3 to 4 months, the patient was followed every 4 to 6 months thereafter. Attempts to discontinue oral therapy over the next several months were unsuccessful, resulting in long term use of oral tetracycline. Approximately 3 months after her last visit, the patient contacted the dermatology office complaining that tetracycline was difficult to use as she sunburned more easily despite applying sunscreen. The dermatology nurse reported this to the dermatologist who changed the patient to oral erythromycin 500 mg twice daily to be administered with food, with instructions to follow up in 6 to 8 weeks. Complications Six days later, the dermatologist was notified by a local emergency room physician that the patient presented with drowsiness, dizziness, ataxia and blurred vision and was admitted to the hospital for observation. Laboratory testing revealed carbamazepine intoxication, related to the co-administration of oral erythromycin, with a serum carbamazepine (Tegretol) level of 21 µg/ml (the therapeutic range is 2 µg/ml to 10 µg/ml). On checking the patient’s record, the dermatologist noted that there was no indication that carbamazepine was used by the patient as it didn’t appear on the medication list that was filled out on the “patient history form” at her first visit. However, after her most recent dermatology visit, and before the telephone order to discontinue tetracycline and start oral erythromycin, the patient’s neurologist changed her therapy for facial pain from phenytoin to carbamazepine. A carbamazepine dosage of 800 mg per day had resulted in clinical improvement, with maintenance of a therapeutic serum level ranging from 6 µg/ml to 8 µg/ml. When she discontinued the oral erythromycin, her symptoms of carbamazepine intoxication resolved within 7 days without any further adverse sequelae. Discussion It’s easy to appreciate how this situation may occur. Overall, erythromycin is a very safe medication. The dermatologist didn’t perceive a risk of prescribing erythromycin to an established patient based on a telephone conversation, knowing that this patient was consistently compliant with follow-up recommendations. Unfortunately, the dermatologist wasn’t aware of the complete picture. It’s important that a patient’s medical history and current medication list be updated before prescribing new therapies. This represents an important issue for physician awareness and education of any office staff who interact with patients and participate in the “chain” of clinical decisions, including telephone interactions.
E ffective treatment of acne and rosacea sometimes requires the use of systemic antibiotic therapy. As acne and rosacea are chronic disorders, oral antibiotic treatment is often continued for several months or longer in order to maintain control of the disease and reduce the frequency and severity of exacerbations. Fortunately, the oral antibiotics that are most commonly prescribed (e.g. tetracyclines, macrolides) are associated with excellent efficacy and safety track records over several decades of use. Once it’s been established that a patient has responded to a given oral agent and has not experienced any adverse effects, therapy is often continued with a high level of comfort. It’s important, however, for the clinician to be aware of potential adverse reactions and clinically significant drug interactions associated with commonly prescribed therapies. The following case, shared with me by a colleague who encountered an uncomfortable experience, represents a significant drug interaction that occurred in a patient treated for acne with a macrolide antibiotic agent. CASE HISTORY A 32-year-old female presented with diffuse facial acne vulgaris that was partially responsive to a variety of prescribed combination topical acne regimens used for several months. Although the superficial acne lesions responded well to topical therapy, the major component of bothersome refractory acne was deeper inflammatory lesions. The use of oral contraceptive therapy (Ortho Tri-Cyclen) over 6 months resulted in minimal therapeutic benefit. Past medical history was significant for allergic rhinitis treated with fexofenadine (Allegra) 60 mg twice daily and an intermittent facial pain (tic) disorder treated with phenytoin (Dilantin) 300 mg twice daily. Oral tetracycline 500 mg twice daily was added to the treatment regimen with excellent results noted at an 8-week follow-up. The patient was maintained on tetracycline therapy thereafter, along with her topical regimen, which included sulfacetamide 10%/sulfur 5% cleanser (Plexion Cleanser) used twice daily, benzoyl peroxide 3% gel (Triaz) applied in the morning and tazarotene 0.05% cream (Tazorac) applied nightly. Once disease control was established for the first 3 to 4 months, the patient was followed every 4 to 6 months thereafter. Attempts to discontinue oral therapy over the next several months were unsuccessful, resulting in long term use of oral tetracycline. Approximately 3 months after her last visit, the patient contacted the dermatology office complaining that tetracycline was difficult to use as she sunburned more easily despite applying sunscreen. The dermatology nurse reported this to the dermatologist who changed the patient to oral erythromycin 500 mg twice daily to be administered with food, with instructions to follow up in 6 to 8 weeks. Complications Six days later, the dermatologist was notified by a local emergency room physician that the patient presented with drowsiness, dizziness, ataxia and blurred vision and was admitted to the hospital for observation. Laboratory testing revealed carbamazepine intoxication, related to the co-administration of oral erythromycin, with a serum carbamazepine (Tegretol) level of 21 µg/ml (the therapeutic range is 2 µg/ml to 10 µg/ml). On checking the patient’s record, the dermatologist noted that there was no indication that carbamazepine was used by the patient as it didn’t appear on the medication list that was filled out on the “patient history form” at her first visit. However, after her most recent dermatology visit, and before the telephone order to discontinue tetracycline and start oral erythromycin, the patient’s neurologist changed her therapy for facial pain from phenytoin to carbamazepine. A carbamazepine dosage of 800 mg per day had resulted in clinical improvement, with maintenance of a therapeutic serum level ranging from 6 µg/ml to 8 µg/ml. When she discontinued the oral erythromycin, her symptoms of carbamazepine intoxication resolved within 7 days without any further adverse sequelae. Discussion It’s easy to appreciate how this situation may occur. Overall, erythromycin is a very safe medication. The dermatologist didn’t perceive a risk of prescribing erythromycin to an established patient based on a telephone conversation, knowing that this patient was consistently compliant with follow-up recommendations. Unfortunately, the dermatologist wasn’t aware of the complete picture. It’s important that a patient’s medical history and current medication list be updated before prescribing new therapies. This represents an important issue for physician awareness and education of any office staff who interact with patients and participate in the “chain” of clinical decisions, including telephone interactions.
