Childhood mefloquine-induced mania and psychosis: a case report

Serious infection may systemically increase noradrenergic signaling and produce psychological effects

Serious infection elicits inflammatory processes that act through a range of molecular pathways, including cytokine signaling. It is not established however that noradrenaline (NA), a widely distributed neurotransmitter in the brain that is also a principal output molecule of the sympathetic nervous system, can produce psychological effects associated with infection. This paper puts forth the hypothesis that through neural-immune crosstalk, serious infection increases noradrenergic signaling, both in the central nervous system and in peripheral organs. In this manner, elevated noradrenergic transmission may help produce basic symptoms of infection such as fever, fatigue, aches and pains (including headache), nausea, and loss of appetite. NA may also promote cognitive impairment, major depression, unipolar mania, and even epileptic seizures in some cases. The paper focuses on three major types of infection: influenza (viral), tuberculosis (bacterial), malaria (parasitic), while also summarizing the potential relationship between NA and human immunodeficiency virus (HIV) infection. Four lines of evidence are used to test association between NA and influenza, tuberculosis, and malaria: direct measures of NA and its metabolites; and incidence of hypertension, bipolar mania, and epileptic seizures, since the latter three conditions may be associated with elevated NA. In addition, heart rate variability data are examined with respect to a number of infectious diseases, since those data provide information on sympathetic nervous system activity. While the data do not unequivocally support elevated noradrenergic signaling promoting psychological symptomatology with infection, many studies are consistent with this view.

Development of a physiologically based pharmacokinetic model for mefloquine and its application alongside a clinical effectiveness model to select an optimal dose for prevention of malaria in young Caucasian children

AIMS

To predict the optimal chemoprophylactic dose of mefloquine in infants of 5-10 kg using physiologically based pharmacokinetic (PBPK) and clinical effectiveness models.

METHODS

The PBPK model was developed in Simcyp version 14.1 and verified against clinical pharmacokinetic data in adults; the final model, accounting for developmental physiology and enzyme ontogeny was then applied in the paediatric population. The clinical effectiveness model utilized real-world chemoprophylaxis data with stratification of output by age and including infant data from the UK population.

RESULTS

PBPK simulations in infant populations depend on the assumed fraction of mefloquine metabolized by CYP3A4 (0.47, 0.95) and on the associated CYP3A4 ontogeny (Salem, Upreti). However, all scenarios suggest that a dose of 62.5 mg weekly achieves or exceeds the exposure in adults following a 250 mg weekly dose and results in a minimum plasma concentration of 620 ng ml^-1 , which is considered necessary to achieve 95% prophylactic efficacy. The clinical effectiveness model predicts a 96% protective efficacy from mefloquine chemoprophylaxis at 62.5 mg weekly.

CONCLUSIONS

The PBPK and clinical effectiveness models are mutually supportive and suggest a prophylactic dose of 62.5 mg weekly in the Caucasian 5-10 kg infant population travelling to endemic countries. This dual approach offers a novel route to dose selection in a vulnerable population, where clinical trials would be difficult to conduct.

Hemoglobins emerging roles in mental disorders. Metabolical, genetical and immunological aspects

Hemoglobin (Hb) expression in the central nervous system is recently shown. Cooccurences of mental disorders (mainly bipolar disorder (BD) and tic disorders) with β- or α-thalassemia trait or erythrocytosis were witnessed, which may be due to peripheral or central hypoxia/hyperoxia or haplotypal gene interactions. β-Globin genes reside at 11p15.5 close to tyrosine hydroxylase, dopamine receptor DRD4 and Brain Derived Neurotrophic Factor, which involve in psychiatric diseases. α-Globin genes reside at 16p13.3 which associates with BD, tic disorders, ATR-16 Syndrome and Rubinstein Taybi Syndrome (RTS). CREB-Binding Protein (CEBBP)-gene is mutated in RTS, which commonly associates with mood disorders. 16p13.3 region also contains GRIN2A gene encoding N-methyl-d-aspartate receptor-2A and SSTR5 (Somatostatin Receptor-5), again involving in mental disorders. We demonstrated a protective role of minor HbA2 against post-partum episodes in BD and association of higher minor HbF (fetal hemoglobin) levels with family history of psychosis in a BD-patient cohort. HbA2 increases in cardiac ischemia and in mountain dwellers indicating its likely protection against ischemia/hypoxia. HMGIY, a repressive transcription factor of δ-globin chain of HbA2 is increased in lymphocytes of schizophrenics. In autism, deletional mutations were found in BCL11A gene, which cause persistence of HbF at high levels in adulthood. Also, certain polymorphisms in BCL11A strongly associate with schizophrenia. Further, many drugs from anabolic steroids to antimalarial agents elevate HbF and may cause mania. We ascribe a protective role to HbA2 and a maladaptive detrimental role to HbF in psychopathology. We believe that future studies on hemoglobins may pave to discover novel pathogenesis mechanisms in mental disorders.

Antimalarial drugs and the prevalence of mental and neurological manifestations: A systematic review and meta-analysis

Background: Antimalarial drugs affect the central nervous system, but it is difficult to differentiate the effect of these drugs from that of the malaria illness. We conducted a systematic review to determine the association between anti-malarial drugs and mental and neurological impairment in humans.  Methods: We systematically searched online databases, including Medline/PubMed, PsychoInfo, and Embase, for articles published up to 14th July 2016. Pooled prevalence, heterogeneity and factors associated with prevalence of mental and neurological manifestations were determined using meta-analytic techniques.  Results: Of the 2,349 records identified in the initial search, 51 human studies met the eligibility criteria. The median pooled prevalence range of mental and neurological manifestations associated with antimalarial drugs ranged from 0.7% (dapsone) to 48.3% (minocycline) across all studies, while it ranged from 0.6% (pyrimethamine) to 42.7% (amodiaquine) during treatment of acute malaria, and 0.7% (primaquine/dapsone) to 55.0% (sulfadoxine) during prophylaxis. Pooled prevalence of mental and neurological manifestations across all studies was associated with an increased number of antimalarial drugs (prevalence ratio= 5.51 (95%CI, 1.05-29.04); P=0.045) in a meta-regression analysis. Headaches (15%) and dizziness (14%) were the most common mental and neurological manifestations across all studies. Of individual antimalarial drugs still on the market, mental and neurological manifestations were most common with the use of sulphadoxine (55%) for prophylaxis studies and amodiaquine (42.7%) for acute malaria studies. Mefloquine affected more domains of mental and neurological manifestations than any other antimalarial drug.  Conclusions: Antimalarial drugs, particularly those used for prophylaxis, may be associated with mental and neurological manifestations, and the number of antimalarial drugs taken determines the association. Mental and neurological manifestations should be assessed following the use of antimalarial drugs.

Antimalarial drugs and the prevalence of mental and neurological manifestations: A systematic review and meta-analysis

Background: Antimalarial drugs affect the central nervous system, but it is difficult to differentiate the effect of these drugs from that of the malaria illness. We conducted a systematic review to determine the association between anti-malarial drugs and mental and neurological impairment in humans.  Methods: We systematically searched online databases, including Medline/PubMed, PsychoInfo, and Embase, for articles published up to 14th July 2016. Pooled prevalence, heterogeneity and factors associated with prevalence of mental and neurological manifestations were determined using meta-analytic techniques.  Results: Of the 2,349 records identified in the initial search, 51 human studies met the eligibility criteria. The median pooled prevalence range of mental and neurological manifestations associated with antimalarial drugs ranged from 0.7% (dapsone) to 48.3% (minocycline) across all studies, while it ranged from 0.6% (pyrimethamine) to 42.7% (amodiaquine) during treatment of acute malaria, and 0.7% (primaquine/dapsone) to 55.0% (sulfadoxine) during prophylaxis. Pooled prevalence of mental and neurological manifestations across all studies was associated with an increased number of antimalarial drugs (prevalence ratio= 5.51 (95%CI, 1.05-29.04); P=0.045) in a meta-regression analysis. Headaches (15%) and dizziness (14%) were the most common mental and neurological manifestations across all studies. Of individual antimalarial drugs still on the market, mental and neurological manifestations were most common with the use of sulphadoxine (55%) for prophylaxis studies and amodiaquine (42.7%) for acute malaria studies. Mefloquine affected more domains of mental and neurological manifestations than any other antimalarial drug.  Conclusions: Antimalarial drugs, particularly those used for prophylaxis, may be associated with mental and neurological manifestations, and the number of antimalarial drugs taken determines the association. Mental and neurological manifestations should be assessed following the use of antimalarial drugs.

Formulation and evaluation of Pheroid vesicles containing mefloquine for the treatment of malaria

OBJECTIVES

Mefloquine (MQ) is an antimalarial drug with high efficacy, often used in the treatment and chemoprophylaxis of malaria. However, it has low solubility in water, a long elimination half-life (4 days), and is neurotoxic, which leads to unwanted side effects.

METHODS

We investigated a lipid-based drug delivery system, Pheroid vesicles, in combination with MQ (Pheroid MQ), to promote future clinical use. MQ was incorporated into Pheroid vesicles and the formulations characterized. The formulations were evaluated in terms of in-vitro efficacy and toxicity. In-vivo bioavailability studies were conducted in C57 BL6 mice.

KEY FINDINGS

The vesicles incorporated MQ with ~63% entrapment efficiency. The IC50 values of MQ after 48-h incubation in chloroquine-resistant (RSA11) and chloroquine sensitive (3D7) strains, were reduced by ~50% and ~30% respectively. In-vivo bioavailability study revealed no change in the pharmacokinetic parameters of MQ, and the incorporation of the drug in Pheroid vesicles reduced the in-vitro haemolytic activity by ~75%. Furthermore, the cytotoxicity against human neuroblastoma cells (SH-SY5Y) of the free drug was reduced by ~64% with Pheroid MQ.

CONCLUSIONS

Pheroid vesicles may therefore decrease the toxicity of MQ and thereby improve its therapeutic index, a strategy that may provide an effective alternative for malaria chemoprophylaxis and treatment.

Establishing pharmacovigilance programs in resource-limited settings: the example of treating malaria

The unprecedented levels of political, technical and financial support for improved malaria control, and particularly for changes in the malaria treatment policy, have heralded a renewed appreciation of the role of pharmacovigilance, its relationship with other areas of public health and the development of novel approaches to addressing the pharmacovigilance priorities in malaria-endemic countries. In order to become a valuable public health activity in these resource-limited settings, pharmacovigilance needs to be viewed within its broadest definition of detecting, understanding and preventing adverse drug reactions and drug-related problems. Pharmacovigilance in resource-limited settings provides an opportunity to identify and address health system failures that significantly impact on patient morbidity and mortality, particularly those that are drug related. Countries need to establish a national strategy that identifies realistic and relevant objectives that meet the most pressing pharmacovigilance needs, taking into consideration the conditions under which these systems are likely to develop.

Atypical manifestations of malaria

Malaria remains a major cause of morbidity and mortality worldwide. The classic presentation of malaria with paroxysms of fever is seen only in 50%-70% of patients. Development of immunity, increasing resistance to antimalarial drugs, and indiscriminate use of antimalarial drugs have led to malaria presenting with unusual features. This review compiles a description of the various atypical manifestations of malaria.

Artesunate-mefloquine combination therapy in acute Plasmodium falciparum malaria in young children: a field study regarding neurological and neuropsychiatric safety

Background

Mefloquine-artesunate combination therapy for uncomplicated falciparum malaria is one of the treatments used in African children. Data concerning neurological safety in adults and children treated with mefloquine and artesunate combination therapy is well documented in Asia. Safety data for neurological and neuropsychiatric side effects of mefloquine and artesunate combination therapy in African children are scarce, although WHO recommends this therapy in Africa.

Methods

A phase IV, open label, single arm study was conducted among African children between 10 and 20 kg with acute uncomplicated falciparum malaria. They were treated over three consecutive days with a paediatric fixed-dose combination of artesunate (50 mg/d) and mefloquine (125 mg/d). Parasitological, clinical and neurological examinations and standardized questions about neuropsychiatric symptoms were carried out on days 0, 4, 7, 28 and 63. The primary objective was to assess the neurological and neuropsychiatric safety of artesunate-mefloquine combination therapy in young children.

Results

From December 2007 to March 2009, 220 children with uncomplicated Plasmodium falciparum malaria were treated with artesunate and mefloquine. 213 children were analysed according to study protocol. 50 neurological and neuropsychiatric adverse events occurred in 28 patients. Eleven drug-related neurological and neuropsychiatric adverse events occurred in eight patients. Sleeping disorders were present in 2.3%, neurological disorders in 1.4%, neuropsychiatric disorders in 1% and eating disorders in 0.5% of the patients. Adverse events were of mild to moderate intensity and resolved spontaneously.

Conclusion

African children showed a low percentage of self-limited neurological and neuropsychiatric adverse events, confirming studies on neurological safety in Asian children treated with artesunate and mefloquine. Sleeping disorders were most frequently observed.