Periactin - is an older antihistamine and one of the "drowsy" h1 blockers .




This is being prescribed more so recently  .

In terms of its positive functions -

1) It is used to treat serotonin syndrome -so for mast cell patients expereincing high serotonin affecting sleep ,mood ,increasing ,pulse and other issues -see contents relased page - could find this medication helpful .


2) periactin is used in myopathy - musles not working due to damaged muscle fibers -  in cancer so this suggests it will help those of us with muscle pain .


these are 2 problems we have poor cover for mediction wise .I will read up on the pharacology for more details .




Must not be prescribed for children as it reduces growth hormone .


Could make depression worse in those with low serotonin constantly or at times .

Caution in those who get winter SAD .


Drops blood pressure due to taking up noradrenaline . -Could be of use in those with hyperadrgenic pots /HEDS as in these individuals nor epinpeherine is high .


Recommended tests and observations

Serotonin in blood on 3 occasions to ensure serotonin isnt low as this will make this worse .

A checklist for symptoms of low serotonin.


In those with HPOTs /HEDS - Caution in those who have blood pressure drops as it will lower further . Patients have replorted low BP sysmptoms with this mediction . So close monitoring of noradrenline levels and blood pressure required





Cyproheptadine has the following interaction information:


Antidepressants, SSRI


cyproheptadine possibly antagonises antidepressant effect of SSRIs - due to lowering serotonin


Cyproheptadine belongs to Antihistamines, Sedating and will have the following interaction information:


Opioid Analgesics


sedative effects possibly increased when sedating antihistamines given with opioid analgesics


Cyproheptadine belongs to Antihistamines and will have the following interaction information:


Note: Sedative interactions apply to a lesser extent to the non-sedating antihistamines. Interactions do not generally apply to antihistamines used for topical action (including inhalation)




increased sedative effect when antihistamines given with alcohol (possibly less effect with non-sedating antihistamines)


Antidepressants, Tricyclic


increased antimuscarinic and sedative effects when antihistamines given with tricyclics


Antidepressants, Tricyclic (related)


possible increased antimuscarinic and sedative effects when antihistamines given with tricyclic-related antidepressants




increased risk of antimuscarinic side-effects when antihistamines given with antimuscarinics


Note: Many drugs have antimuscarinic effects; concomitant use of two or more such drugs can increase side-effects such as dry mouth, urine retention, and constipation; concomitant use can also lead to confusion in the elderly. Interactions do not generally apply to antimuscarinics used by inhalation




Anxiolytics and Hypnotics


increased sedative effect when antihistamines given with anxiolytics and hypnotics




antihistamines theoretically antagonise effect of betahistine




antihistamines theoretically antagonise effects of histamine—manufacturer of histamine advises avoid concomitant use




increased antimuscarinic and sedative effects when antihistamines given with MAOIs


Note: For interactions of reversible MAO-A inhibitors (RIMAs) see Moclobemide, and for interactions of MAO-B inhibitors see Rasagiline and Selegiline; the antibacterial Linezolid is a reversible, non-selective MAO inhibitor



SSRI /SSNI medictions increase serotonin and norepinpeherine .So pericatin reducing both of these will act against SSRI/SSNI antidepressnats .  These drugs must NOT be stoped quickly .As this is dangerous .So discuss this with your doctor -with this reference -

Opiod analgesics - morphine ,pethidine , codine ,fentenyl




Tricyclic antidepressnats - Amityptylline ,Nortryptylline


Anxiolytics and Hypnotics


Sedative antihistamines with these increase drowsiness so it poses a risk of being seriosly drowsy .


Opiod analgesics ,tricyclic antidepressnats ,anxolytics and hypnotics must not be stopped suddenly .Please discuss this with your doctor or contact me directly

Antimuscarinic - Anticholinergic side effects


Block -neurotransmitter acetylcholine in the central and the peripheral nervous system.


Anticholinergics are a class of medications that inhibit parasympathetic nerve impulses by selectively blocking the binding of the neurotransmitter acetylcholine to its receptor in nerve cells. The nerve fibers of the parasympathetic system are responsible for the involuntary movements of smooth muscles present in the gastrointestinal tract, urinary tract, lungs, etc.


So these meds (as well as periactin) have anticholinergic effects .

Betahistdine becomes histamine inside the body and histamine -

Both work against the positive effects of antihistamines

Drug specific

Drug class specific