MAOIs Antihistamines

MAOIs ANTIHISTAMINES t occurrence of antimuscarinic effects such as blurred vision, confusion (in elderly patients), restlessness and constipation Additive antimuscarinic effects Warn patients and carers, particularly those managing elderly patients... 

MAOIs ANTIHISTAMINES -SEDATIVE Additive depression of CNS ranging from drowsiness to coma and respiratory depression Synergistic depressant effects on CNS function Necessary to warn patients, particularly regards activities that require attention, e.g. driving or using machinery and equipment that could cause self-harm... 

As with other sedative antihistamines (see MAOIs + Antihistamines , above), the UK manufacturers of cyproheptadine also say that MAOIs prolong and intensify the antimuscarinic effects of antihistamines, but fhere seems to be no clinical data to support this. 

There is an increase in anticholinergic effects when antihistamines are administered with the monamine oxidase inhibitors (MAOIs) and additive sedative effects if administered with central nervous system depressants (eg, narcotic analgesics or alcohol). When cimetidine and loratadine are administered together there is a risk for increased loratadine levels. 

Mianserin was the first of the second-generation antidepressants to be developed. It lacked the amine reuptake inhibitory and MAOI actions of the first-generation drugs and also lacked the cardiotoxicity and anticholinergic activity of the TCAs. However, it was sedative (antihistaminic), caused postural hypotension (alpha-1 blockade) and also caused blood dyscrasias and agranulocytosis in a small number of patients. This has limited the use of mianserin in recent years. 

Uses Allergic Rxns itching Action Phenothiazine antihistamine serotonin antagonist Dose Adults. 4-20 mg PO qSh max 0.5 mg/kg/d Feds. 2-6 y 2 mg bid-tid (max 12 mg/24 h) 7-14 y 4 mg bid-tid in hepatic impair Caution [B, ] BPH Contra Neonates or <2 y NAG BOO acute asthma GI obst Disp Tabs, syrup SE Anticholinergic, drowsiness Interactions T Effects Wf CNS depressants, MAOIs, EtOH X effects OF epi, fluoxetine EMS Use other CNS depressants w/ caution concurrent EtOH use can T CNS depression higher epi doses may be needed if used OD May cause mood changes, Szs, CNS depression, or CNS stimulation symptomatic and supportive... 

Dextromethorphan (Mediquell, Benylin DM, PediaCare 1, Delsym, Others) [OTC] [Antitussive] Uses Control nonproductive cough Action Suppresses medullary cough center Dose Adults. 10-30 mg PO q4h PRN (max 120 mg/24 h) Peds. 2-6 y 2.5-7.5 mg q4-8h (max 30 mg/24 h) 7-12 y 5-10 mg q4-8h (max 60 mg/24/h) Caution [C, /-] Not for persistent or chronic cough Contra < 2 y. Disp Caps, lozenges, syrup, Liq SE GI disturbances Interactions T Effects W/ amiodarone, fluoxetine, quinidine, terbinafme T risk of serotonin synd Wf sibutramine, MAOIs T CNS depression Wf antihistamines, antidepressants, sedative, opioids, EtOH EMS Will not affect cough caused by asthma,... 

Hyoscyamine (Anaspaz, Cystospaz, Levsin, Others) [Antispasmodic/Anticholinergic] Uses Spasm w/ GI bladder disorders Action Anticholinergic Dose Adults. 0.125-0.25 mg (1-2 tabs) SL/PO tid-qid, ac hs 1 SR cap ql2h Caution [C, +] T Effects w/ amantadine, antihistamines, antimuscarinics, haloperidol, phenothiazines, TCA, MAOI Contra BOO, GI obst, NAG, MyG, paralytic ileus, ulcerative colitis, MI Disp Caps, tabs SE Dry skin, xerostomia, constipation, anticholinergic SE, heat prostration w/ hot weather Interactions T Effects W/ amantadine, antimuscarinics, haloperidol, phenothiazines,... 

Uses Endogenous depression Action TCA T synaptic CNS levels of serotonin /or norepinephrine Dose Adults. 25 mg PO tid-qid >150 mg/d not OK Elderly. 10-25 mg hs Peds. 6-7 y 10 mg/d 8-11 y 10-20 mg/d >11 y 25-35 mg/d, 4- w/ hepatic insuff Caution [D, +/-] NAG, CV Dz Contra TCA allergy, use w/ MAOI Disp Caps, soln SE Anticholinergic (blurred vision, retention, xerostomia) Interactions T Effects W/ antihistamines, CNS depressants, cimetidine, fluoxetine, OCP, phenothiazine, quinidine, EtOH T effects OF anticoagulants T risk of HTN W/clonidine, levodopa, sympathomimetics T effects W/barbiturates, carbamazepine, rifampin EMS Concurrent use w/ MAOIs have resulted in HTN,... 

Temazepam (Restoril) [C-IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia, anxiety, depression, panic attacks Action Benzodiaz ine Dose 15-30 mg PO hs PRN X in elderly Caution [X, /-] Potentiates CNS dqjressive effects of opioids, barbs, EtOH, antihistamines, MAOIs, TCAs Contra NAG Disp Caps SE Confusion, dizziness, drowsiness, hangover Interactions T Effects W/ cimetidine, disulfiram, kava kava, valerian T CNS depression W/ anticonvulsants, CNS depressants, EtOH t effects OF haloperidol, phenytoin X effects W/ aminophylline, dyphylline, OCPs, oxtriphylline, rifampin, theophylline, tobacco X effects OF levodopa EMS Use caution w/ other benzodiazepines, antihistamines, opioids and verapamil, can T CNS depression concurrent EtOH can T CNS depression abruptly D/C after >10 d use may cause withdrawal OD May cause profound CNS depression, confusion, bradycardia, hypotension, and altered reflexes flumazenil can be used as antidote, activated charcoal may be effective... 

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