Haloperidol hydrochloride

Haloperidol hydrochloride is an antipsychotic drug that has similar actions to the antipsychotic medicine phenothiazine [1].

Haloperidol hydrochloride has been reported to play a role as an inverse agonist of dopamine. In addition, Haloperidol hydrochloride has been found to be highlt potent neuroleptic by relieving nervous through the depression of nerve function. Besides, Haloperidol hydrochloride has shown about 50-fold potency than chiorpromazine, the other antipsychotic drug. Haloperidol hydrochloride has shown beneficial effects in the treatment of delusions and hallucinations. These effects are mainly achieved through blockage of dopamine receptors in the mesocortex and limbic system. Haloperidol hydrochloride has been revealed to prevent the effects of dopamine in the nigrostriatal pathways, which probably explains the associated side effects such as akathisia and dystonias[1].

References:
[1] Dr Ananya Mandal, MD .Haloperidol Pharmacology.

Compatibility of cholecalciferol, haloperidol, imipramine hydrochloride, levodopa/carbidopa, lorazepam, minocycline hydrochloride, tacrolimus monohydrate, terbinafine, tramadol hydrochloride and valsartan in SyrSpend SF PH4 oral suspensions.[Pubmed:27209697]

Pharmazie. 2016 Apr;71(4):185-91.

A challenge with compounding oral liquid formulations is the limited availability of data to support the physical, chemical and microbiological stability of the formulation. This poses a patient safety concern and a risk for medication errors. The objective of this study was to evaluate the compatibility of the following active pharmaceutical ingredients (APIs) in 10 oral suspensions, using SyrSpend SF PH4 (liquid) as the suspending vehicle: cholecalciferol 50,000 IU/mL, haloperidol 0.5 mg/mL, imipramine hydrochloride 5.0 mg/mL, levodopa/carbidopa 5.0/1.25 mg/mL, lorazepam 1.0 mg/mL, minocycline hydrochloride 10.0 mg/mL, tacrolimus monohydrate 1.0 mg/mL, terbinafine 25.0 mg/mL, tramadol hydrochloride 10.0 mg/mL and valsartan 4.0 mg/mL. The suspensions were stored both refrigerated (2 - 8 degrees C) and at controlled room temperature (20 - 25 degrees C). This is the first stability study for these APIs in SyrSpend SF PH4 (liquid). Further, the stability of haloperidol,ilmipramine hydrochloride, minocycline, and valsartan in oral suspension has not been previously reported in the literature. Compatibility was assessed by measuring percent recovery at varying time points throughout a 90 days period. Quantification of the APIs was performed by high performance liquid chromatography (HPLC-UV). Given the percentage of recovery of the APIs within the suspensions, the beyond-use date of the final preparations was found to be at least 90 days for most suspensions both refrigerated and at room temperature. Exceptions were: Minocycline hydrochloride at both storage temperatures (60 days), levodopa/carbidopa at room temperature (30 days), and lorazepam at room temperature (60 days). This suggests that compounded suspensions of APIs from different pharmacological classes in SyrSpend SF PH4 (liquid) are stable.

Pharmacokinetic and pharmacodynamic interactions among haloperidol, carteolol hydrochloride and biperiden hydrochloride.[Pubmed:10495985]

Nihon Shinkei Seishin Yakurigaku Zasshi. 1999 Jul;19(3):111-8.

A beta-adrenoceptor blocker and an anticholinergic agent are often prescribed concomitantly for the treatment of neuroleptic-induced akathisia. The aim of this study was to investigate possible pharmacokinetic interactions of neuroleptic haloperidol with the beta-blocker carteolol and the anticholinergic biperiden. In a 5-step, open-labeled, oral single-dose study, eight healthy male volunteers received 2 mg haloperidol, 10 mg carteolol hydrochloride, and 2 mg biperiden hydrochloride: first each drug alone, then a combination of haloperidol and carteolol, and then all three drugs concurrently. Serum concentrations of haloperidol, carteolol, and biperiden were determined up to 24 hr postdosing, and a safety evaluation was conducted throughout the study. Carteolol increased the area under the haloperidol serum concentration-time curve (AUC0-t) 1.4-fold (P = 0.0014) and decreased the serum clearance of haloperidol up to 67% (P = 0.0127). Biperiden reduced the serum haloperidol concentrations increased by the administration of carteolol. No significant changes of the serum pharmacokinetics of carteolol and biperiden were found as a result of any drug combinations. Adverse events of the central nervous system such as sleepiness and changes in pupil size were observed, but all were mild with clinical insignificance.

[Effects of mianserin hydrochloride on delirium: comparison with the effects of oxypertine and haloperidol].[Pubmed:7975931]

Nihon Shinkei Seishin Yakurigaku Zasshi. 1994 Aug;14(4):269-77.

Mianserin (10-60 mg), haloperidol (2-6 mg) and oxypertine (20-60 mg) were administered once before bedtime in patients with delirium in Kurume University Hospital. The therapeutic effects of these drugs were investigated in the pre- and post-treatment using Delirium Rating Scale (DRS: Trzepacz et al., 1988). Mianserin was observed to be effective on 67% of the cases, and haloperidol and oxypertine in about 60%. Based on the clinical results and on the measurement of plasma concentration of mianserin, mianserin was considered to be an effective drug particularly against delirium in elderly patients because the effect and plasma concentration of mianserin were observed in the early stage of treatment without any side effects. The reduction of plasma free-MHPG was accompanied with improvement in the delirious state. The reason for the changes in plasma free-HVA was unclear.

Subtype-selective inhibition of N-methyl-D-aspartate receptors by haloperidol.[Pubmed:8967976]

Mol Pharmacol. 1996 Dec;50(6):1541-50.

Previous studies indicate that haloperidol, a therapeutically useful antipsychotic drug, inhibits neuronal N-methyl-D-aspartate (NMDA) responses and has neuroprotective effects against NMDA-induced brain injury. To further characterize this inhibition, we used electrical recordings to assay the effects of haloperidol on four diheteromeric subunit combinations of cloned rat NMDA receptors expressed in Xenopus laevis oocytes: NR1A coexpressed with NR2A, NR2B, NR2C, or NR2D. Haloperidol selectively blocks NR1A/2B subunit combinations (IC50 = approximately 3 microM; maximum inhibition, approximately 85%), whereas the other subunit combinations are > or = 100-fold less sensitive (IC50 = >300 microM). Inhibition of NR1A/2B receptors is insurmountable with respect to glutamate and glycine and does not exhibit voltage dependence. The splice variant combinations NR1B/2B and NR1e/2B are also blocked by haloperidol. In oocytes from some frogs, 30-100 microM haloperidol induces potentiation of NR1A/2A receptor responses. NMDA responses in E16-17 rat cortical neurons cultured for < or = 10 days are inhibited by haloperidol at the same potency and to the extent as NR1/2B receptors (IC50 = approximately 2 microM; maximum inhibition, approximately 80%). In contrast, cells cultured for longer periods show a wide range of sensitivity. This change in pharmacology coincides with a developmental switch in subunit expression; from NR1 expressed with NR2B to NR1 coexpressed with NR2A and NR2B. Inhibition of macroscopic neuronal NMDA responses is mechanistically similar to inhibition of NR1A/2B receptors. Single-channel recordings from neurons show that antagonism is associated with a decrease in the frequency of channel openings and a shortening of mean channel open time. Collectively, our experiments indicate that haloperidol selectively inhibits NMDA receptors comprised of NR1 and NR2B subunits. Inhibition is consistent with action at a noncompetitive allosteric site that is distinct from the glutamate-, glycine-, and phencyclidine-binding sites and is probably mechanistically related to the atypical antagonist ifenprodil. Our results suggest that haloperidol can be used as a tool for investigating NMDA receptor subunit composition and can serve as a structural lead for designing novel subtype-selective NMDA receptor ligands.

Inhibition of N-methyl-D-aspartate receptors by haloperidol: developmental and pharmacological characterization in native and recombinant receptors.[Pubmed:8858988]

J Pharmacol Exp Ther. 1996 Oct;279(1):154-61.

The dopaminergic antagonist haloperidol also acts at the psychotomimetic sigma receptor and has been proposed to act at N-methyl-D-aspartate (NMDA) receptors. We have investigated the basis of its action at NMDA receptors using native and recombinant receptors and as a function of brain development. Haloperidol inhibits binding of 125I-(+) MK 801 to NMDA receptors formed from NR 1a/2B with high affinity but has lower affinity at receptors formed from NR 1a/2A. No differences are noted between different NR 1 splice variants transfected with NR 2B. Differences are also seen between neonatal receptors and adult receptors; neonatal receptors are inhibited by haloperidol with an IC50 value that is 50 times lower than that of adult receptors. Other agents acting at the sigma receptor inhibit binding of 125I-(+) MK 801 to NMDA receptors, and are slightly more potent at neonatal receptors. However, the rank order of potency for sigma agents at sigma receptors does not match their rank order of potency at NMDA receptors, and the prototypic sigma ligand ditolylguanidine shows no preference between NR 1a/2A and NR 1a/2B receptors. This suggests that haloperidol exerts its effects on the NMDA receptor at a distinct site from the pharmacologically defined sigma receptor. The effects of haloperidol are also modified by spermidine noncompetitively, which differs from the effects of spermidine on ifenprodil-mediated inhibition of NMDA receptors. This suggests that haloperidol interacts with NMDA receptors at a site distinct from the polyamine or ifenprodil sites.

Dopamine receptor pharmacology.[Pubmed:7940991]

Trends Pharmacol Sci. 1994 Jul;15(7):264-70.

Dopamine receptors are the primary targets in the treatment of schizophrenia, Parkinson's disease, and Huntington's chorea, and are discussed in this review by Philip Seeman and Hubert Van Tol. Improved therapy may be obtained by drugs that selectively target a particular subtype of dopamine receptor. Most antipsychotic drugs block D2 receptors in direct correlation to clinical potency, except clozapine, which prefers D4 receptors. D1 and D2 receptors can enhance each other's actions, possibly through subunits of the G proteins. In schizophrenia, the D2 and D3 receptor density is elevated by 10%, while the D4 receptor density is elevated by 600%. Therefore, D4 receptors may be a target for future antipsychotic drugs. While antipsychotics originally helped to discover dopamine receptors, the five cloned dopamine receptors are now facilitating the discovery of selective antipsychotic and antiparkinson drugs.

Haloperidol decanoate. A preliminary review of its pharmacodynamic and pharmacokinetic properties and therapeutic use in psychosis.[Pubmed:3545764]

Drugs. 1987 Jan;33(1):31-49.

Haloperidol decanoate is a depot preparation of haloperidol, a commonly used butyrophenone derivative with antipsychotic activity. Haloperidol decanoate has no intrinsic activity: its pharmacodynamic actions are those of haloperidol--primarily that of central antidopamine activity. The monthly administered depot formulation has several clinical and practical advantages over oral haloperidol: better compliance and more predictable absorption; more controlled plasma concentrations; fewer extrapyramidal side effects; less frequent reminders of condition; and reduced medical workload. In open and controlled studies, haloperidol decanoate has produced adequate maintenance or improvement of the condition of patients with psychoses (mainly schizophrenia) when an abrupt change from orally administered haloperidol or other antipsychotic drugs has been instituted. Limited comparative studies indicate that the depot and oral forms of haloperidol are equally effective, and that haloperidol decanoate is at least as effective as depot forms of fluphenazine, pipothiazine, flupenthixol and perphenazine in controlling the symptoms of psychosis. Extrapyramidal side effects and the need for concomitant anti-Parkinsonian drugs may be a problem, but may be less frequent than with oral haloperidol or other depot antipsychotics. Thus, haloperidol decanoate offers a useful alternative in the treatment of psychoses to orally administered haloperidol or to other depot antipsychotic drugs.