Evaluation of symptoms and symptom combinations in histamine intolerance

BACKGROUND/AIMS: Food intolerance/malabsorption, particularly histamine intolerance (HIT), may cause nonspecific functional gastrointestinal and extraintestinal symptoms. We evaluated gastrointestinal and extraintestinal symptoms in patients with HIT. METHODS: In an analysis of outpatients' charts we identified 133 patients, who presented with recurring nonspecific functional gastrointestinal, extraintestinal symptoms, and a diamine oxidase value <10 U/mL, indicative of HIT. A standardized anonymous questionnaire with symptoms of HIT based on known symptoms and the 4 histamine receptors including gastrointestinal, cardiovascular, respiratory and skin complaints was developed, and sent by mail to the patients. RESULTS: In the 62 patients that completed the questionnaire, bloating was the most common and most serious symptom. Other commonly reported gastrointestinal symptoms were postprandial fullness, diarrhea, abdominal pain, and constipation. The presence of 2 from a list of 24 symptoms resulted in 276 various symptom combinations. From calculated 2.024 possible combinations of 3 symptoms the patients with HIT presented 1.975 combinations. CONCLUSIONS: The knowledge of this wide variability of symptoms and complex symptom combinations in patients with HIT may help to clinically recognize and diagnose HIT.

Pharmacogenetic Correlates of Antipsychotic-Induced Weight Gain in the Chinese Population / 神经科学通报·英文版

Antipsychotic-induced weight gain (AIWG) is a common adverse effect of this treatment, particularly with second-generation antipsychotics, and it is a major health problem around the world. We aimed to review the progress of pharmacogenetic studies on AIWG in the Chinese population to compare the results for Chinese with other ethnic populations, identify the limitations and problems of current studies, and provide future research directions in China. Both English and Chinese electronic databases were searched to identify eligible studies. We determined that > 25 single-nucleotide polymorphisms in 19 genes have been investigated in association with AIWG in Chinese patients over the past few decades. HTR2C rs3813929 is the most frequently studied single-nucleotide polymorphism, and it seems to be the most strongly associated with AIWG in the Chinese population. However, many genes that have been reported to be associated with AIWG in other ethnic populations have not been included in Chinese studies. To explain the pharmacogenetic reasons for AIWG in the Chinese population, genome-wide association studies and multiple-center, standard, unified, and large samples are needed.

Successful Remission of Recurrent Anaphylaxis after Omalizumab Administration in a Patient with Systemic Mastocytosis / 대한내과학회지

Mastocytosis is a disorder characterized by abnormal mast cell proliferation and accumulation in one or more tissues. It presents in two major variants: cutaneous mastocytosis and systemic mastocytosis. Because the symptoms are related to mast cells, histamine receptor antagonists and leukotriene receptor antagonists are recommended as therapeutic options. Here, we report a 54-year-old male patient with a history of urticaria pigmentosa who presented with recurrent anaphylaxis. His serum tryptase level was 31.7 ng/mL and mast cell infiltration was observed in his bone marrow. He had frequent attacks of anaphylaxis despite treatment with ketotifen, levocetirizine, and montelukast. Symptoms related to systemic mastocytosis were controlled and the patient exhibited no recurrence of anaphylaxis following the introduction of monthly omalizumab injection. Omalizumab can be considered as a treatment option in patients with systemic mastocytosis unresponsive to conventional oral medications.

Targeting Histamine Receptors in Irritable Bowel Syndrome: A Critical Appraisal

Irritable bowel syndrome is a group of functional gastrointestinal disorders with not yet fully clarified etiology. Recent evidence suggesting that mast cells may play a central role in the pathogenesis of irritable bowel syndrome paves the way for agents targeting histamine receptors as a potential therapeutic option in clinical treatment. In this review, the role of histamine and histamine receptors is debated. Moreover, the clinical evidence of anti-histamine therapeutics in irritable bowel syndrome is discussed.

Effects of cetirizine in dogs with chronic atopic dermatitis: a randomized, double blind, placebo-controlled trial

This study was conducted to evaluate the effects of cetirizine in dogs with atopic dermatitis (AD) while fulfilling Favrot's diagnostic clinical criteria. Dogs received either 3 mg/kg cetirizine (n = 27), or a placebo (n = 23) orally once daily for 14 days in a randomized, double blind, placebo-controlled study, without concomitant medication. The effects were evaluated using a pruritus visual analog scale at the start (day 0) and at day 14. After 14 days, cetirizine clearly had no effect on the pruritus in dogs with chronic AD, and there was no significant difference between groups. These findings indicated that cetirizine (and likely H1 histamine receptor antagonists in general) should not be recommended for the control of pruritus in dogs with long term allergies.

The Modulatory Role of Spinally Located Histamine Receptors in the Regulation of the Blood Glucose Level in D-Glucose-Fed Mice

The possible roles of spinal histamine receptors in the regulation of the blood glucose level were studied in ICR mice. Mice were intrathecally (i.t.) treated with histamine 1 (H1) receptor agonist (2-pyridylethylamine) or antagonist (cetirizine), histamine 2 (H2) receptor agonist (dimaprit) or antagonist (ranitidine), histamine 3 (H3) receptor agonist (alpha-methylhistamine) or antagonist (carcinine) and histamine 4 (H4) receptor agonist (VUF 8430) or antagonist (JNJ 7777120), and the blood glucose level was measured at 30, 60 and 120 min after i.t. administration. The i.t. injection with alpha-methylhistamine, but not carcinine slightly caused an elevation of the blood glucose level. In addition, histamine H1, H2, and H4 receptor agonists and antagonists did not affect the blood glucose level. In D-glucose-fed model, i.t. pretreatment with cetirizine enhanced the blood glucose level, whereas 2-pyridylethylamine did not affect. The i.t. pretreatment with dimaprit, but not ranitidine, enhanced the blood glucose level in D-glucose-fed model. In addition, alpha-methylhistamine, but not carcinine, slightly but significantly enhanced the blood glucose level D-glucose-fed model. Finally, i.t. pretreatment with JNJ 7777120, but not VUF 8430, slightly but significantly increased the blood glucose level. Although histamine receptors themselves located at the spinal cord do not exert any effect on the regulation of the blood glucose level, our results suggest that the activation of spinal histamine H2 receptors and the blockade of spinal histamine H1 or H3 receptors may play modulatory roles for up-regulation and down-regulation, respectively, of the blood glucose level in D-glucose fed model.

Histamine Promotes the Release of Interleukin-6 via the H1R/p38 and NF-kappaB Pathways in Nasal Fibroblasts

PURPOSE: Based on the close relationship between histamine and interleukin 6 (IL-6), we hypothesized that histamine may regulate the production of cytokines, such as IL-6, during allergic inflammation. Here, we examined the role of histamine in IL-6 production and histamine receptor activity in nasal fibroblasts, along with the mechanisms underlying these effects. METHODS: Experiments were performed using nasal fibroblasts from 8 normal patients. RT-PCR was used to identify the major histamine receptors expressed in nasal fibroblasts. Fibroblasts were then treated with histamine with or without histamine-receptor antagonists, and monitored for IL-6 production using an ELISA. Four potential downstream signaling molecules, p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and NF-kappaB, were evaluated by Western blot, and a luciferase reporter assay. RESULTS: Elevated expression was seen for all histamine receptors, with IL-6 protein levels increasing significantly following histamine stimulation. Among the histamine-receptor specific antagonists, only the H1R antagonist significantly decreased IL-6 production in histamine-stimulated nasal fibroblasts. Histamine increased the expression level of phosphorylated p38 (pp38), pERK, and pJNK, as well as NF-kappaB induction. The H1R antagonist actively suppressed pp38 and NF-kappaB expression in histamine-induced nasal fibroblasts, but not pERK and pJNK. The p38 inhibitor strongly attenuated IL-6 production in histamine-stimulated nasal fibroblasts. CONCLUSIONS: The data presented here suggest that antihistamines may be involved in the regulation of cytokines, such as IL-6, due to the role of histamine as an inflammatory mediator in nasal fibroblasts.

Antihistamínicos Parte 1 - Historia y características de los receptores histaminérgicos / Antihistamines. Part 1 - History and characteristics of histaminergic receptors

Los antihistamínicos han sido usados durante los últimos 50 años y se han convertido en los medicamentos de mayor prescripción en el mundo. En este artículo se revisa el desarrollo de nuestro conocimiento referente a la histamina en el transcurso del siglo, como mediador biológico almacenado y liberado mayormente por los basófilos y mastocitos; mediador biológico situado en diferentes tejidos corporales, y otras células, con un papel fisiológico fundamental en el control de la secreción de ácido gástrico y un papel fisiopatológico en una gama de trastornos alérgicos. La síntesis y estudios farmacológicos de agonistas y antagonistas selectivos han establecido la existencia de cuatro tipos de receptores de histamina y antagonistas de ellos, que han encontrado muy importantes aplicaciones terapéuticas. Debido al aumento de la prevalencia de las enfermedades alérgicas según el Libro Blanco de Alergia (WAO), se deben crear normas que promuevan el uso de los antihistamínicos de manera adecuada y racional. De esta manera, la correcta elección debe ser realizada de acuerdo a su eficacia, tolerabilidad, seguridad, grupo etario, situaciones y precauciones particulares en pacientes con algún riesgo incrementado. El crear normas que promuevan una práctica terapéutica óptima o uso racional de dichos medicamentos. Elegirlos de acuerdo a su eficacia, tolerabilidad, seguridad, grupo etario, situaciones y precauciones especiales en pacientes portadores de ciertas enfermedades de riesgo a utilizarlos.(AU)

Antihistamines have been used for the last 50 years and have become the most prescribed medications in the world. In this article we review the development of our knowledge regarding histamine in the course of the century, as a biological mediator stored and released mostly by basophils and mast cells; biological mediator located in different body tissues, and other cells, with a fundamental physiological role in the control of gastric acid secretion and a physiopathological role in a range of disorders allergic The synthesis and pharmacological studies of selective agonists and antagonists have established the existence of four types of histamine receptors and antagonists of them, who have found very important therapeutic applications. Due to the increased prevalence of allergic diseases according to the White Paper on Allergy (WAO), standards should be created that promote the use of antihistamines in an adequate and rational way. In this way, the correct choice must be made in accordance to its efficacy, tolerability, safety, age group, situations and special precautions in patients with an increased risk. The creation of norms that promote an optimal therapeutic practice or rational use of said medications. Choose them according to their effectiveness, tolerability, safety, age group, situations and special precautions in patients with certain risk diseases to use them.

Characteristics in Molecular Vibrational Frequency Patterns between Agonists and Antagonists of Histamine Receptors

To learn the differences between the structure-activity relationship and molecular vibration-activity relationship in the ligand-receptor interaction of the histamine receptor, 47 ligands of the histamine receptor were analyzed by structural similarity and molecular vibrational frequency patterns. The radial tree that was produced by clustering analysis of molecular vibrational frequency patterns shows its potential for the functional classification of histamine receptor ligands.

Revisão sobre a efícacia e segurança dos anti-histamínicos de primeira e segunda geração / Revision on efficacy and safety of antihistamines of first and second generation

Objetivo: Revisar a eficácia e segurança dos principais anti-histamínicos de primeira e segunda geração. Os anti-histamínicos correspondem a um grupo extenso de medicamentos que vêm apresentando grandes avanços no conhecimento de suas ações e estão entre os agentes mais utilizados na prática clínica em diversas doenças alérgicas. Método: Levantamento bibliográfico nos bancos de dados PubMed, Medline, LILACS, SCIELO e capítulos de livros nos últimos 10 anos, sendo incluídos artigos históricos. Resultados: Nessa revisão são destacadas as principais características da histamina, as diferenças entre os receptores de histamina, o desenvolvimento dos anti-histamínicos de primeira e segunda geração, sua classificação e os principais efeitos colaterais de cada grupo de anti-histamínicos. Conclusão: A presente revisão não pretende esgotar o assunto sobre eficácia e segurança dos anti-histamínicos, mas destaca a falta de estudos bem conduzidos sobre eficácia dos anti-histamínicos de primeira geração e o número crescente de metanálises sobre farmacodinâmica, potência, eficácia e segurança dos anti-histamínicos de segunda geração.

Objective: To review the efficacy and safety of the main antihistamines of first and second generation. The antihistamines represent an extensive group of drugs that are showing great advances in knowledge of their actions and are among the most common agents used in clinical practice in various allergic diseases. Method: Searches in PubMed, Medline, LILACS, SCIELO database and book chapters in the last 10 years, including historic articles. Results: This review highlights the main features of histamine, the differences between histamine receptors, development of first and second generation antihistamines, their classification, and the main side effects of each group of antihistamines. Conclusion: The present review is not intended to exhaust the subject on efficacy and safety of antihistamine, but it highlights the lack of well conducted studies of the efficacy of first-generation antihistamine and the rising number of meta-analysis of pharmacodynamics, potency, efficacy and safety of second-generation antihistamines.

Histamina, receptores de histamina e anti-histamínicos: novos conceitos / Histamine, histamine receptors and antihistamines: new concepts

As drogas com ação anti-histamínica estão entre as medicações mais comumente prescritas na prática dermatológica diária, tanto em adultos como em crianças. Este artigo aborda os novos conceitos da função dos receptores de histamina (receptores H1) e discute os efeitos anti-inflamatórios dessas drogas. A segunda geração de anti-histamínicos difere da primeira geração devido a sua elevada especificidade e afinidade pelos receptores H1 periféricos e devido a seu menor efeito no sistema nervoso central, tendo como resultado menores efeitos sedativos. Embora a eficácia dos diferentes anti-histamínicos H1 (anti-H1) no tratamento de doentes alérgicos seja similar, mesmo quando se comparam anti-H1 de primeira e de segunda geração, eles são muito diferentes em termos de estrutura química, farmacologia e propriedades tóxicas. Consequentemente o conhecimento de suas características farmacocinéticas e farmacodinâmicas é importante para a melhor prática médica, especialmente em gestantes, crianças, idosos e doentes com comorbidades.

Drugs with antihistamine action are the most commonly prescribed medication in daily dermatologic practice, both to adults and children. This article addresses new concepts of the role of histamine receptors (H1 receptors) and discusses the anti-inflammatory effects of these drugs. Second generation antihistamines differs from first generation because of their high specificity and affinity for peripheral H1-receptors. Second generation antihistamines are also less likely to produce sedation because they have less effect on the central nervous system. Although the efficacy of the various H1-antihistamines in the treatment of allergic patients is similar, even when comparing first- and second-generation drugs, these drugs are still very different in terms of their chemical structure, pharmacology and toxic properties. Consequently, knowledge of their pharmacokinetic and pharmacodynamic characteristics is essential for a better medical care, especially that offered to pregnant women, children, the elderly, and patients with comorbidities.

Different expression of histamine H4 receptor in nasal mucosa in allergic rhinitis patients / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To observe expression and distribution of histamine H4 receptor in nasal mucosa in normal people and allergic rhinitis patients,and understand role of histamine H4 receptor in allergic rhinitis.@*METHOD@#Select normal people and allergic rhinitis patients each 10, take the nasal mucosa, detect expression and distribution of histamine H4 receptor at proteins and transcription level respectively by immunohistochemical method and RT-PCR, and compared.@*RESULT@#Histamine H4 receptor at proteins and transcription level were found in normal nasal mucosa (25 509 +/- 6 441, 0.42 +/- 0.08), increased significantly in nasal mucosa of allergic rhinitis patients (49 676 +/- 8 541, 0.69 +/- 0.11, P < 0.05), which in structural cells and immune cells.@*CONCLUSION@#Histamine H4 receptors exist in normal nasal mucosa, its express significantly enhance, flew histamine H4 receptor may be mediated histamine in pathogenesis of allergic rhinitis ,who is one of the ligands of histamine.

Histamine receptors; responses and modulations towards agonist and antagonist on the rabbit ileum, in vitro study

This research work deals with the mechanism of action involved in determining the therapeutic potential of histamine and its blockers in gastrointestinal motility. Rabbits of equal weights were used in this study. They were brought from the animal house of BMSI, sacrificed in the Pharmacology Research laboratory. lleum strip were isolated and with special recommended methodology, longitudinal and circular muscles were separated. Individual muscle strip were then exposed separately to the desired drugs in the organ bath and reading were recorded on the polygraph machine. Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi. 1996 to 1998. Histamine increases the contractile effects of longitudinal and circular muscle. H[1] and H[2] blockers potentiate its effects on longitudinal muscle while in circular muscle no change was observed with H[1] blocker whereas H[2] blocker antagonized the histaminic effects. However when H[1] blocker applied directly it increases the amplitude of contraction in longitudinal and circular muscle whereas H[2] blocker decreases the height of contractions. Histamine in the presence of H[1] and H[2] blocker augmented their effects in longitudinal muscle and antagonizes in circular layer. Gastrointestinal motility can be controlled through histamine and its antagonist. New drugs can be formulated on the basis of this study for the regulation of intestinal motility

Effect of histamine H4 receptor and its antagonist on allergic rhinitis in rats / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To clarify the effect of histamine H4 receptor antagonist, JNJ 7777120, and histamine H1 receptor antagonist, Loratadine, on allergic rhinitis (AR) in rats and to study the role of histamine H4 receptor antagonist and histamine H1 receptor antagonist in the pathogenesis of allergic rhinitis and therapeutic value of their antagonist.</p><p><b>METHODS</b>AR animal model were induced by ovalbumin (OVA) in the Wistar rats, which treated with histamine H4 receptor antagonist and (or) histamine H1 receptor antagonist. The allergic symptoms (sneezing and nasal rubbing), serum total IgE and the levels of cytokines in serum or nasal lavage fluid were measured, the diversity between two groups were observed. Statistical analysis was performed using a SPSS 13.0 software.</p><p><b>RESULTS</b>Compared with AR group with no treatment, the inhibition of nasal symptoms (P < 0.01), a significant decrease in the levels of IgE, IL-4 in serum and Eotaxin in nasal lavage fluid (P < 0.01), a significant increase in the levels of IFN-γ in serum (P < 0.01) after treatment was found. Compared with group treated with Loratadine, inhibition of nasal symptoms (q value were 3.72, 4.16, P < 0.01), a significant increase in the levels of IgE and IL-4 in serum (q value were 8.01, 4.96, P < 0.05), a significant decrease in the levels of IFN-γ in serum (q = 3.18, P < 0.05) in group treated with JNJ 7777120 also, but no significant differences in the levels of Eotaxin in nasal lavage fluid (P > 0.05). Administration of JNJ 7777120 and Loratadine jointly, neither additive effect nor synergistic action were found (P > 0.05).</p><p><b>CONCLUSIONS</b>Histamine H4 receptor is closely related with allergic rhinitis and is important in the pathogenesis of allergic rhinitis, the same as histamine H1 receptor. Histamine H4 receptor antagonist, JNJ 7777120, could relieve symptoms and inflammatory conditions in allergic rhinitis, the effect was weak compared with Loratadine. Neither additive effect nor synergistic action were found between them.</p>

role of central endogenous histamine and H[1], H[2] and H[3] receptors on food intake in broiler chickens

The role of endogenous histamine and H[1], H[2] and H[3] central receptors on food intake in broiler chickens was investigated. For this purpose, a probe was used to manipulate the concentration of endogenous histamine by intracerebroventricular [ICV] injection of thioperamide, an H[3] receptor antagonist, and R-alpha-methylhistamine, an H[3] receptor agonist and subsequently the effects of brain histaminergic system on food intake was assessed. Moreover, to determine the receptors involved in histamine-induced feeding behaviour changes, H[1], and H2 blockers were administered to thioperamide-treated chickens. Injection of thioperamide [600 and 300 nmol] decreased food intake dose-dependently [P<0.05]. On the contrary, ICV injection of R-alphamethylhistamine [400 and 200 nmol] increased food intake [P<0.05]. Chlorpheniramine [128 and 256 nmol], a H[1] receptor antagonist, increased food intake [P<0.05]. Famotidine, a H[2] receptor antagonist at 74 or 148 nmol had no effect on food intake but at 296 nmol significantly decreased food intake [P<0.05]. Pretreatment with chlorpheniramine [256 nmol] significantly attenuated thioperamide effects [600 nmol] on food intake [P<0.05]. In conclusion, the results of the present study demonstrated that histamine exerts anorexigenic effects through H[1], but not H[2] receptors in broiler chickens. Furthermore, it was shown that thioperamide through stimulation of synthesis and release of endogenous neuronal histamine can decrease food intake in broiler chickens

A Case of Hemodynamically Unstable Bradycardia after Risperidone Overdose

Risperidone is an atypical antipsychotic medication commonly used to treat psychotic illness, such as schizophrenia. It has strong serotonin and dopamine receptor antagonism and antagonist activity at alpha-adrenergic receptors and histamine receptors. An overdose of risperidone can cause tachycardia, hypertension, hypotension, prolonged QT interval, and bradycardia. Risperidone overdose is rare,but life-threatening. Here, we present the rare case of a 33- year-old woman who ingested risperidone overdose for the purposes of suicide, developing hemodynamically unstable bradycardia with trifascicular block, leading to fatality. Lessons from our case report are of urgent consideration for temporary pacemaker insertion, and use of alpha-1 agonist, such as phenylephrine in cases of hemodynamically unstable bradycardia by risperidone overdose. Prompt and appropriate identification and interventions are essential for the successful management of risperidone overdose.

Histamine and spontaneously released mast cell granules ffect the cell growth of human hepatocellular carcinoma cells

The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H1 and H2 and that the selective H1 antagonist terfenadine reverted the histamine-induced inhibition of HuH-6 cell growth, whereas the selective H2 antagonist ranitidine inhibited the histamine-induced cell growth of HA22T/VGH cells. We demonstrated that histamine down-regulated the expression of beta-catenin, COX-2 and survivin in HuH-6 cells and that this was associated with caspase-3 activation and PARP cleavage. On the contrary, in HA22T/VGH cells expression of survivin and beta-catenin increased after treatment with granule remnants and histamine. Overall, our results suggest that mediators stored in mast cell granules and histamine may affect the growth of liver cancer cells. However, mast cells and histamine may play different roles depending on the tumor cell features. Finally, these data suggest that histamine and histamine receptor agonists/antagonists might be considered as "new therapeutic" drugs to inhibit liver tumor growth.

Prevention of ischemia-reperfusion injury in rat skin island flap: comparison of histamine receptor blocking agents with l-arginine

Treatment of Molluscum Contagiosum with High Dose Cimetidine Therapy / 대한피부과학회지

BACKGROUND: Molluscum contagiosum is often a difficult problem for dermatologists to treat. Cimetidine is a H2 histamine receptor antagonist that has been used mainly to treat peptic ulcer disease. The use of cimetidine in the treatment of molluscum contagiosum has been reported previously using a dose of 40 mg/kg/day, and has the advantage of being painless and easy to administer, especially for recurrent, extensive, facial and eyelid lesions. OBJECTIVE: The purpose of this study was to evaluate the clinical effects of high dose cimetidine therapy for molluscum contagiosum. METHODS: Twenty patients with molluscum contagiosum were treated using high dose cimetidine therapy (14 females, 6 males; age range 2~16 years). RESULTS: Of the 20 patients who completed the study, 12 patients (60%) showed complete remission, 3 patients (15%) showed partial remission and 5 patients (25%) showed no response. Five out of 8 patients with atopic dermatitis showed complete remission and one showed partial remission. Of the 12 patients without atopic dermatitis, 7 showed complete remission and 2 showed partial remission. CONCLUSION: High dose cimetidine therapy is an effective treatment modality for molluscum contagiosum, and has no severe adverse effects.

Treatment of Verruca Plana with High Dose Cimetidine Therapy / 대한피부과학회지

BACKGROUND: It is often a difficult problem for dermatologists to treat verruca plana. Cimetidine is a H2 histamine receptor antagonist that has been used mainly to treat peptic ulcer disease. The successful use of cimetidine in the treatment of viral warts has been reported previously using doses of 40mg/kg/day and has the advantage of being painless and easy to administer. OBJECTIVE: The purpose of this study was to evaluate the clinical effects of high dose cimetidine therapy for verruca plana. METHODS: Thirty-six patients with verruca plana were treated with high dose cimetidine therapy (22 females, 14 males; age range 7-56 years). RESULTS: Of the 36 patients who completed the study, 15 patients (41.7%) showed complete remission. 8 patients (22.2%) showed partial remission. There was no significant differences among the complete remission, the partial remission and the no response groups. There were a few adverse effects including transient liver enzyme elevation and gynecomastia which were normalized after the cimetidine was discontinued. CONCLUSION: High dose cimetidine therapy is an effective treatment modality for verruca plana without severe adverse effects.