Prenatal and developmental toxicity study of meclizine and caffeine combination in female albino wistar rats.

Meclizine and caffeine combination is used for the treatment of morning sickness. Both compounds are teratogenic and caffeine is known to possess anti-fertility activity also. The present study was undertaken to evaluate the reproductive toxic effect of meclizine and caffeine combination. Three doses were taken for the study; low dose (LD; meclizine 3.7 mg/kg and caffeine 3 mg/kg) was selected from commercially available formulation, middle dose (MD; meclizine 37 mg/kg and caffeine 30 mg/kg) and high dose (HD; meclizine 370 mg/kg and caffeine 300 mg/kg). The mixture was administered 1-7 days and 8-14 days for fertility and embryotoxic studies respectively. Laparotomy was done on 10th day of gestation period. Number of implants and corpora lutea were counted, pre and post-implantation losses were determined. In embryo toxicity study fetuses were evaluated for external, skeletal and visceral examination. High dose was removed from both fertility and embryotoxicity studies due to its severe toxicity to the dam. Significant anti-fertility activity was observed at middle dose. Embryotoxicity study showed significant reduction in fetal body weight, body length and body mass index, dam body weight gain on gestation day 14. Absolute kidney weight in MD and absolute and relative spleen weight in both LD and MD were significantly reduced. There was no increase in external or internal congenital anomalies at both LD and MD. The, results suggest that prescription of meclizine and caffeine for morning sickness in early pregnancy should be reviewed carefully.

A randomized placebo-controlled double-blind pilot study of methotrexate in the treatment of H1 antihistamine-resistant chronic spontaneous urticaria.

Background: Chronic urticaria not responsive to antihistamines is a diffi cult disease to manage. Methotrexate has been used in diffi cult chronic urticarias with some benefi t. Objective: To evaluate the effi cacy of methotrexate in the treatment of chronic spontaneous urticaria poorly responsive to H1 antihistaminics. Methods: In a randomized double-blind trial at the Department of Dermatology and Venereology of a tertiary care centre, 29 patients with chronic spontaneous urticaria not responding well to H1 antihistaminics were recruited. Patients were randomly allocated to receive either a weekly dose of oral methotrexate 15 mg or placebo (calcium carbonate) for a total duration of 12 weeks, after which treatment was stopped and patients were followed up for relapse of urticaria. Each group also received levocetrizine 5 mg once daily for symptom control. Primary outcome measured was a reduction by >2/3rd of baseline urticaria scores after 12 week therapy. Secondary outcome was a reduction in antihistamine requirement after stopping therapy. Results: Fourteen patients were randomized to the methotrexate group and fi fteen patients to the placebo group. Out of 17 patients who completed therapy, the primary outcome was achieved by 3.5 ± 1.9 (out of 10) patients in the methotrexate group and by 3.67 ± 1.03 (out of 7) patients in the placebo group (P > 0.05). Ten patients followed up, after stopping therapy, for a mean period of 3.5 ± 2.4 months; 3 remained in remission and 7 had relapsed. One patient had uncontrollable nausea and vomiting after taking methotrexate and was withdrawn from the study. The placebo group did not experience any side effects. Conclusions: Methotrexate 15 mg weekly for 3 months did not provide any additional benefi t over H1 antihistamines in this study but an adequately powered study with longer follow up is required to assess its utility.

Chloroquine resistant Plasmodium falciparum malaria in Osogbo Nigeria: efficacy of amodiaquine + sulfadoxine-pyrimethamine and chloroquine + chlorpheniramine for treatment

Chloroquine (CQ) resistance in Plasmodium falciparum contributes to increasing malaria-attributable morbidity and mortality in Sub-Saharan Africa. Despite a change in drug policy, continued prescription of CQ did not abate. Therefore the therapeutic efficacy of CQ in uncomplicated falciparum malaria patients was assessed in a standard 28-day protocol in 116 children aged between six and 120 months in Osogbo, Southwest Nigeria. Parasitological and clinical assessments of response to treatment showed that 72 (62.1 percent) of the patients were cured and 44 (37.9 percent) failed the CQ treatment. High initial parasite density and young age were independent predictors for early treatment failure. Out of the 44 patients that failed CQ, 24 received amodiaquine + sulphadoxine/pyrimethamine (AQ+SP) and 20 received chlorpheniramine + chloroquine (CH+CQ) combinations. Mean fever clearance time in those treated with AQ+SP was not significantly different from those treated with CH+CQ (p = 0.05). There was no significant difference in the mean parasite density of the two groups. The cure rate for AQ+SP group was 92 percent while those of CH+CQ was 85 percent. There was a significant difference in parasite clearance time (p = 0.01) between the two groups. The 38 percent treatment failure for CQ reported in this study is higher than the 10 percent recommended by World Health Organization in other to effect change in antimalarial treatment policy. Hence we conclude that CQ can no more be solely relied upon for the treatment of falciparum malaria in Osogbo, Nigeria. AQ+SP and CH+CQ are effective in the treatment of acute uncomplicated malaria and may be considered as useful alternative drugs in the absence of artemisinin-based combination therapies.

Granular parakeratosis presenting with facial keratotic papules.

A 27-year-old female presented with pruritic keratotic papules over the left side of the face since one month. The lesions developed a few days after working in a hot humid environment and were preceded by severe uncontrollable pruritus for which she had repeatedly wiped the area with handkerchiefs and towels. A biopsy from one of the keratotic papules revealed granular parakeratosis with a markedly thick stratum corneum that had parakeratosis and also housed keratohyaline granules. Similar changes were seen in keratotic plugs of dilated follicular infundibula.

Premedication for coronary angiography: effects on anxiety and hemodynamic status.

AIM: This study was designed to compare the outcomes of two current methods of premedication, for coronary angiography with placebo, on the level of anxiety and hemodynamic status. METHODS AND RESULTS: In all, 151 patients referring for coronary angiography were randomized into three groups with equal populations. The first group (group M) received 0.02 mg/kg intravenous midazolam; the second (group DP7rpar; received intramuscular injection of 5mg diazepam + 25 mg promethazine; and the third (group P) received 2cc of intravenous normal saline solution. Vital signs, blood pressure, and peripheral O2 saturation were recorded in specifically-designed questionnaires. The level of anxiety before and after angiography was documented according to the Visual Analog Scale. Patients in the group M accidentally had higher pre-procedural anxiety level (p < 0.05). There was no significant difference in pulse rate, respiratory rate, and mean blood pressure (BP) between these groups prior to angiography. In the group M, diastolic BP decreased more significantly than the other 2 groups during angiography (p < 0.05). Although number of punctures, pain at catheterization site, dose of lidocaine, level of consciousness, and patient satisfaction did not show a significant difference between the three groups; midazolam induced higher level of amnesia than the other 2 groups and the physicians were more satisfied with it only compared with diazepam + promethazine (p < 0.05). CONCLUSION: Because of the importance of hemodynamic stability and comfort during angiography, non-pharmacologic approaches are preferred. In case of severity and persistence of autonomic system stimulation, the least effective dose of midazolam for a short period of time may be used.

Enhancement of the antimalarial efficacy of amodiaquine by chlorpheniramine in vivo

Resistance in Plasmodium falciparum to amodiaquine (AQ) can be reversed in vitro with with antihistaminic and tricyclic antidepressant compounds, but its significance in vivo is unclear. The present report presents the enhancement of the antimalarial efficacy of AQ by chlorpheniramine, an H1 receptor antagonist that reverses chloroquine (CQ) resistance in vitro and enhances its efficacy in vivo, in five children who failed CQ and/or AQ treatment, and who were subsequently retreated and cured with a combination of AQ plus CP, despite the fact that parasites infecting the children harboured mutant pfcrtT76 and pfmdr1Y86 alleles associated with AQ resistance. This suggests a potential clinical appliation of the reversal phenomenon.

Effects of pyrimethamine-sulphadoxine, chloroquine plus chlorpheniramine, and amodiaquine plus pyrimethamine-sulphadoxine on gametocytes during and after treatment of acute, uncomplicated malaria in children

The effects of pyrimethamine-sulphadoxine (PS), chloroquine plus chlorpheniramine, a H1 receptor antagonist that reverses chloroquine resistance in Plasmodium falciparum in vitro and in vivo (CQCP), and amodiaquine plus pyrimethamine-sulphadoxine (AQPS) on gametocyte production were evaluated in 157 children with acute, symptomatic, uncomplicated falciparum malaria who were treated with these drugs. PS was significantly less effective than CQCP or AQPS at clearing asexual parasitaemia or other symptoms of malaria. Gametocyte carriage on days 3, 7, and 14 were significantly higher in those treated with PS. The ratio of the density (per æl blood) of peripheral young gametocyte (PYG), that is, < stage III to peripheral mature gametocyte (PMG), that is, stage IV and V, an index of continuing generation of gametocytes, rose to 1 by day 7 of treatment in those treated with PS, but remained consistently below 1 in the other treatment groups. PYG-PMG density ratio increased significantly from day 0-14 in those treated with PS and CQCP (chi2 = 76, P = 0.000001 and chi2 = 42.2, P = 0.00001, respectively) but decreased significantly in those treated with AQPS (chi2 = 53.2, P = 0.000001). Both PS-sensitive and -resistant infections generated PYG (18 of 29 vs 13 of 20, chi2 = 0.04, P = 0.93) but PYG was present only in those with resistant response to CQCP. Combination of PS with amodiaquine (AQ), that is, (AQPS) resulted in less production of PYG, but in this setting, PYG was not indicative of response to AQPS. These data indicate that PS enhanced production or release of young gametocytes when used alone, but generated less young gametocytes when used in combination with AQ. PYG may be used as an indicator of response to CQCP but not PS or PS-based combination drugs.

The efficacy and safety of 30 mg fexofenadine HCl bid in pediatric patients with allergic rhinitis.

Allergic rhinitis is one of the most common chronic disorders in children. It is also one of the most common causes of absence from school. This study reports on the efficacy and safety of a twice-daily oral dose of fexofenadine HCl 30 mg in Asian children aged 6-11 years diagnosed with seasonal or perennial allergic rhinitis. A total of 100 children with a history of allergic rhinitis for more than one year and a positive prick skin test response to at least one of the common aeroallergens in Thailand were enrolled in this multi-center, open-label, non comparative study. The severity of individual symptoms such as sneezing, rhinitis, etc. and adverse events were recorded in diary cards by the patients in form of scores as well as by the investigator at each visit. The total symptom score (TSS) with or without blocked nose at baseline, week 1 and week 2 was recorded. The TSS was defined as the sum of the individual symptom scores except for the nasal blockage score, as nasal blockage was not expected to respond to antihistamine treatment. Only patients with a total symptom score > or = 6 were included in the study. There was a statistically significant improvement at p < 0.01 for the TSS with or without blocked nose and for each symptom score such as blocked nose, sneezing, rhinorrhea, itchy nose/palate and/or throat, and itchy/watery/red eyes from baseline to week 1 and week 2. Additionally, there was a statistically significant improvement between week 1 and week 2 for itchy nose/palate and/or throat and itchy/watery/red eyes (p < 0.05). The Kappa measure of agreement was statistically significant at p < 0.001 between investigator's and patient's/parent's assessment, indicating the same degree of satisfaction with the overall effectiveness of the treatment. Fexofenadine 30 mg bid is effective in reducing the total symptom score of allergic rhinitis including blocked nose and is generally well tolerated. It is not cardiotoxic and is safe for pediatric patients as young as 6 years of age.

A comparative study of the side effects between pseudoephedrine in Loratadine plus Pseudoephedrine Sulfate Repetabs Tables and loratadine + pseudoephedrine tablet in treatment of allergic rhinitis in Thai patients.

The objective of the study was to evaluate the adverse reactions of Loratadine plus Pseudoephedrine Sulfate Repetabs Tables (LTD+PSE Repetabs) (Loratadine 5 mg + Pseudoephedrine 120 mg) twice daily with that of loratadine (5 mg) twice daily and pseudoephedrine (60 mg) quarter daily in the treatment of patients with allergic rhinitis. The study was designed as an investigator-blind, parallel group study. In this study, 56 patients were equally separated into 2 groups and treated for 14 days with either LTD+PSE Repetabs or loratadine + pseudoephedrine tablet. Both groups were comparable in age, gender, weight; baseline systolic blood pressure, diastolic blood pressure and pulse rate. The change of systolic blood pressure, diastolic blood pressure, and pulse rate did not reach clinical significance throughout the study period. There was no significant difference in occurrences of insomnia, palpitation, mouth dryness and anxiety. However, the incidence of patients with tremor at day 14 in the loratadine + pseudoephedrine tablet group was significantly higher than the LTD+PSE Repetabs group (39% vs 10.7%, p-value = 0.03). Furthermore, one patient in the loratadine + pseudoephedrine tablet group had to discontinue medication at day 7 due to insomnia. In conclusion, LTD+PSE Repetabs is well tolerated and has fewer adverse effects when compared to the loratadine + pseudoephedrine tablet.

A double-blind, placebo-controlled, and randomized study of loratadine (Clarityne) syrup for the treatment of allergic rhinitis in children aged 3 to 12 years.

Allergic rhinitis is a common disease in children, and antihistamines are the key medication. However, traditional tablets are not convenient and lead to low compliance in young children. The aim of this double-blind, placebo-controlled, parallel, randomized study was to evaluate the effectiveness and safety of loratadine syrup for the treatment of children aged 3 to 12 years with allergic rhinitis. Sixty children with allergic rhinitis due to dust mites were enrolled. They were randomized into 2 parallel groups: one group received loratadine syrup 5 mg or 10 mg daily for 3 weeks, and the other group received placebo. The patients returned to special clinics for symptoms evaluation at day 7 and day 21, and the parents were requested to record disease severity daily. Both evaluations, physician's and parents', were recorded with a 4-point scale for 5 symptoms: sneezing, rhinorrhea, nasal congestion, nasal itching and ocular symptoms. Forty-six patients completed the study, 22 in the loratadine group and 24 in the placebo group. At the initial visit, the total symptom score (TSS) in both groups was not significantly different (p = 0.39). The TSS of the loratadine syrup group at day 7 and day 21 was lower than those of the placebo group (p = 0.003, p = 0.06). The daily card scores in the experimental group were also significantly lower than those of the placebo group (week 1, p = 0.014; week 2, p = 0.029; week 3, p = 0.014). No adverse reactions were recorded in both groups. This study revealed that loratadine syrup 5 mg or 10 mg once a day improved symptom scores of children with allergic rhinitis effectively and safely.

Multicenter study of the efficacy and safety of fexofenadine 60 mg. twice daily in 108 Thai patients with chronic idiopathic urticaria.

Fexofenadine is a non-sedating antihistamine indicated for relieving symptoms from allergic conditions with a rapid onset of action without cardiotoxic risks. Controlled studies showed that fexofenadine 180 mg daily provides significant relief of symptoms of chronic idiopathic urticaria (CIU). The purpose of this study was to demonstrate the efficacy and safety of fexofenadine 60 mg twice daily in Thai patients with CIU in a multicenter trial. Patients were assigned to receive twice daily doses of fexofenadine 60 mg for 6 weeks. Patients rated symptom severity every night, investigators rated patients' signs and symptoms at recruitment and at 1, 3 and 6 weeks. Ninety eight out of 108 patient (90.7%) completed the study. The patients reported 95 per cent improvement and, of those, 91 per cent had very favorable responses (excellent 15%, very good 42%, good 30%, fair 8%). The objective assessment by their physicians paralleled those responses. Fexofenadine provided a rapid clinical response that was significantly superior to before treatment in relieving symptoms of CIU (p < 0.001). Adverse events occurred in 20 cases (18.5%), mostly mild headache and drowsiness. Fexofenadine 60 mg twice daily provides effective relief of the symptoms of CIU with minimal adverse events.

A non-comparative trial of the efficacy and safety of fexofenadine for treatment of perennial allergic rhinitis.

An open-label, non-comparative study was performed in three Otolaryngology centers in Bangkok, Thailand, to assess the efficacy, safety and tolerability of fexofenadine in Thai patients with perennial allergic rhinitis. Altogether 101 perennial allergic rhinitis patients were included, 33 males and 68 females. Mean age was 33 years, average duration of symptoms was 6 years. All patients received fexofenadine hydrochloride 120 mg once daily (OD) in the morning for 2 weeks. Patients recorded their allergy symptoms daily using a 5 point rating scales in the diary card. At the end of 2 weeks, patients and investigators assessed the overall efficacy of treatment. Adverse events and onset of symptom relief were also recorded by every patient. Blood test and ECG were performed before and after treatment in one center (Siriraj Hospital). Total symptom scores and nasal scores decreased significantly from a baseline at 1 week and 2 weeks after treatment (p < 0.05). The mean onset of symptom relief was 2 hours and 12 minutes. The global assessment of the treatment by patients and investigators showed significant concordance. There was no significant change in either the vital signs, laboratory tests or ECG. The incidence of treatment related adverse events was 8% but all were mild and easily tolerated. Drowsiness was reported from only one patient. This study suggests that fexofenadine 120 mg once daily was an effective, safe and well tolerated treatment for perennial allergic rhinitis in Thai patients.

The changing face of antihistamines and cardiac adverse drug reactions: a clinical perspective.

Recent times have witnessed a qualitative shift in the recognition and management of adverse drug effects. Many of them occur in organs that are unconnected to the primary target of pharmacological action. Out of these, cardiac side-effects have drawn particular attention because of their potential to cause death. Starting with the early observations on antibiotics such as macrolides, followed by fluoroquinolones and others, the focus has now shifted to the antihistamine class of drugs which are used extensively by patients all over the world, thanks to the ever increasing levels of environmental pollution. The occurrence of prolonged QTc interval following treatment with terfenadine leading to ventricular tachycardia of torsades de points variety with a potentially fatal outcome has forced many regulatory authorities of the world to clamp a ban the use of this drug. Alerted by these developments, studies on a new member, followed by fluoroquinolones and others, the focus has now shifted to the antihistamine class of drugs which are used extensively by patients all over the world, thanks to the ever incresing levels of envrionmental pollution. The occurrence of prolonged QTc interval following treatment with terfenadine leading to ventricular tachycardia of torsades de points variety with a potentially fatal outcome has forced many regulatory authorities of the world to clamp a ban use of this drug. Alerted by these developments, studies on a new member of non-sedating antihistamine class viz, fexofenadine, have been reviewed especially because of the structural similarity between terfenadine and fexofenadine. It is now clear that despite the closeness of its chemical structure to terfenadine fexofenadine behaves in a different manner and does not affect the electrophysiology of the heart muscle tissue, as proved by data from extensive clinical trials as well as membrane models in vitro. Interestingly, the solitary false alarm that was sounded on the drug by a group of workers in the Netherlands was later rectified by the same group. Clinically speaking, the cardiovascular safety of fexofenadine has been convincingly demonstrated at various dose levels and various time intervals, alone and together with other drugs of potential toxigenicity. All things put together, it appears reasonable to conclude that fexofenadine is free from cardiovascular ADRs of clinical significance. It could also be concluded that cardiac side-effects of antihistamines is not a class effect.

Possible role of histamine receptors in the central regulation of immune responses.

The present study was designed to delineate the role of H1- and H2-histamine receptors in the neuro-immune regulation in rats. The effects of H1- and H2-receptor antagonists on humoral and cell-mediated immune (HI and CMI) responses were investigated after intraperitoneal (i.p.) and intra-cerebroventricular (i.c.v.) administration. HI response was assayed by anti-sheep red blood cell (SRBC) antibody titre in presence and absence of 2-mercaptoethanol (2-ME). The CMI responses were evaluated by delayed type hypersensitivity (DTH) reaction (in vivo), i.e., measurement of footpad thickness, and lymphokine activity such as leucocyte migration inhibition (LMI) test (in vitro). On i.p. administration, both H1- (pheniramine and astemizole) and H2-receptor antagonists (ranitidine and cimetidine) were observed to produce significant enhancement of anti-SRBC antibody response. However, only H2- and not H1-receptor blockers were observed to stimulate CMI response significantly. When administered by icv route, only H2-receptor antagonists caused a statistically significant increase in both HI and CMI responses, while the H1-receptor blockers failed to modify the same. Thus, H2-receptors appear to play a major role in the histaminergic mechanisms involved in immunomodulation both at the level of immunocompetent cells active in the peripheral tissues as well as through the central nervous system structures involved in the central regulation of neuro-immune interaction.

Beneficial effects of diphenhydramine in dystonia

The objective of this paper was to evaluate the efficacy of diphenhydramine hidrochloride (DPH) in dystonic patients. In 1995, Truong et al reported encouraging results in five patients with idiopathic torsion dystonia (ITD) treated with DPH, an H1 antagonist with sedative and anticholinergic properties. Five patients with generalized ITD, one with secondary generalized dystonia and one with idiopathic segmental dystonia were included in the prospective study, initialy the response to intravenous administration of DPH versus placebo in two sessions a week apart was evaluated. Two weeks later all patients started oral DPH in increasing doses (range 100-300 mg, mean 164 mg). The degree of dystonia was determined by a modified University of Columbia Scale evaluating the baseline score, after placebo and DPH I.V. administration then at one and six months after starting oral treatment. The results were analyzed by Friedman's test for repated measurements. On comparing scores for baseline severity, I.V. placebo and I.V. DPH presented a highly significant correlation (12.09; p = 0.00) as well as comparing baseline score with oral DPH at one and 6 months, treatment (12.78; p = 0.00). Functional score results were 9.5 p = 0.01 and 8.4 p = 8.4 p = 0.02 at one and 6 months respectively. The most common side effects were sommolence and dizziness. It can be concluded that DPH proved effective in our patients with mild to moderate adverse effects not requiring drug withdrawal in any case. However, I.V. challenge was unable to predict the long-term response to oral medication perhaps due to the limited number of cases.

Effect of current on dermal permeation of positively charged liposomes.

Transdermal permeation of positively charged liposomally entrapped diphenhydramine hydrochloride (DPH-HCL) has been investigated in presence of pulse D.C. anodic current. Positively charged liposomes were prepared by lipid film hydration technique with stearyl amine as a charge inducer. The prepared liposomes were then subjected to in vitro permeation studies using artificial membrane (cellophane membrane) and human cadaver skin under the influence of iontophoretic current. The effect of variable current density as well as time frequency of application of current onto the release pattern of the plain drug and charged liposomally entrapped drug were studied and the results were compared. The results indicate that application of pulse D.C. anodic current significantly influences the transfer of positively charged liposomally entrapped DPH-HCL across HCS.