Use of retinoids in the treatment of psoriasis

The limitations of conventional therapy for psoriasis are reviewed, and the pharmacology, pharmacokinetics, clinical efficacy, adverse effects, dosing and therapeutic monitoring of etretinate and other retinoids are described. Traditional treatments for psoriasis include topical application of anthralin and coal tar ointments; systemic therapy with corticosteroids or methotrexate; and systemic or methotrexate; and systemic psoralens combined with exposure to ultraviolet light (PUVA). The topical therapies are beneficial but aesthetically displeasing to patients; the systemic treatments are associated with severe adverse reactions. Etretinate provides another option in the treatment of psoriasis. Etretinate and acitretin, an investigational retinoid, appear to be effective oral therapies for severe variants of psoriasis, especially pustular psoriasis. Retinoids generally do not offer substantial therapeutic advantages over other treatments for chronic-plaque psoriasis. The most common adverse effects of etretinate are cheilitis, alopecia, desquamation of the skin, drying of mucous membranes, and pruritus. Use of low-dose etretinae in combination with other forms of therapy, such as corticosteroids or PUVA, may minimize the frequency of adverse effects. Etretinate is a known teratogen. Its elimination half-life is prolonged to 100-120 days with long-term use. Acitretin, the carboxylic acid derivative of etretinate, has a much shorter elimination half-life than etretinate (50 hours after multiple doses). Its adverse-effect profile is similar to that of etretinate. Etretinate and acitretin appear to be clinically effective for therapy of severe variants of psoriasis. Etretinate should not be used to treat mild psoriasis because of the high incidence of serious adverse effects.     

US-guided percutaneous biopsy: use of a screw biopsy stylet to aid needle detection

Insertion of a screw biopsy stylet into a thin-walled biopsy needle greatly enhances detection of the needle during ultrasound-guided percutaneous biopsy. This technique is helpful when precise needle-tip localization is needed for biopsies of small lesions.     

Systemic absorption of inhaled epinephrine

To determine the systemic absorption of epinephrine when it is given by inhalation, six normal volunteers were given 15 puffs, followed by 30 puffs, of epinephrine from a pressurized aerosol (160 micrograms epinephrine/puff). The peak mean (+/- SE) plasma epinephrine levels were 1.50 (+/- 0.61) and 4.22 (+/- 1.93) nmol/L 1 minute after each dose, respectively. The effect on physiologic finger tremor correlated with the plasma epinephrine level and returned to baseline 20 minutes after taking the higher dose. There was a small fall in mean plasma potassium levels of 0.45 mmol/L and a small rise in plasma glucose levels of 0.81 mmol/L. On a separate occasion an injection of 0.3 ml of 1/1000 (300 micrograms) epinephrine was given subcutaneously to the same individuals. This caused a peak plasma epinephrine level of 2.43 (+/- 0.47) nmol/L at 10 minutes, and this was still raised at 2.05 (+/- 0.41) nmol/L after 40 minutes. The maximum fall in the mean plasma potassium level was 0.43 mmol/L after the injection.     

Primary tooth fluorosis in 5-year-old schoolchildren in Ireland.

AIM: This was to determine the prevalence of primary tooth fluorosis in the dentitions of 5-year-old schoolchildren. A subsidiary aim was to investigate whether an association existed between the presence of primary tooth fluorosis, fluoridation status, infant feeding practices or the oral hygiene practices of the child. STUDY DESIGN: A cross-sectional and stratified by fluoridation status study. METHODS: Fluorosis was recorded using a modification of the Tooth Surface Index of Fluorosis (TSIF). Demographic data, information on infant feeding practices and oral hygiene practices were collected via a parental questionnaire. STATISTICS: Stepwise logistic regression analysis. RESULTS: Fluorosis prevalence in the fluoridated group (n=208) was 32%; 29.3% (n=61) had a modified TSIF score of 1; 2.4% (n=5) had a modified TSIF score of 2; and 1% (n=1) had a modified TSIF score of 5. In the non-fluoridated group (n=86) one child had a modified TSIF score of 1. Primary tooth prevalence of fluorosis in the entire sample (n=294) was 23%. Factors that were associated with primary tooth fluorosis were: fluoridation status (p= 0.0003, 95% CI = 5-281) and the age at which toothbrushing with toothpaste commenced (p = 0.016, 95% C.I. 1.1 - 3.8). No association with infant feeding practices was identified. CONCLUSION: The overall prevalence of primary tooth fluorosis was 23%. Lifetime residence in a fluoridated area and commencement of toothbrushing with toothpaste between 12 and 18 months of age were associated with primary tooth fluorosis. No association with infant feeding practices was identified.     

Profound acidosis caused by isoniazid ingestion

Isoniazid (INH) is the cause of one of the most common serious drug overdoses and can cause severe metabolic acidosis. We report a case of INH overdose that is most notable because the patient survived without apparent sequelae after experiencing an extremely low pH level (6.49). This is the lowest reported pH level with patient survival. Toxicity and pharmacology of INH and various aspects of metabolic acidosis are discussed.     

Sedative doses of remifentanil have minimal effect on ECoG spike activity during awake epilepsy surgery.

The use of remifentanil for sedation during awake epilepsy surgery has been described in a case report. However, little information is available regarding the effect of remifentanil on the quality of intraoperative electrocorticography (ECoG). This study was designed to investigate the effect of sedative doses of remifentanil on ECoG interictal spike activity among patients undergoing awake anterior temporal lobectomy for refractory epilepsy. Ten adult patients were studied prospectively. After baseline EcoG recordings were obtained, remifentanil was administered as a continuous infusion at 0.1 microg/kg/min and the ECoG recorded continuously for 15 minutes. Recordings obtained before and during the administration of remifentanil were compared with respect to spike frequency and location. A trend toward a small decrease in spike frequency was observed as patients became increasingly somnolescent and background ECoG activity slowed. The difference was not statistically significant. Blood pressure and heart rate were not adversely affected by the administration of remifentanil. Respiratory rates decreased in all patients (mean decrease, 8 breaths/min) and one patient transiently developed a respiratory rate of 4 breaths per minute that elicited a decrease in the rate of remifentanil administration. Remifentanil administered at sedation doses does not adversely affect intraoperatively recorded interictal spike activity. Further investigation of the use of this drug during awake epilepsy surgery is warranted.