The male had difficulties releasing his grip, childhood-onset neuromyotonia and muscle stiffness, progressive motor neuropathy, finger cramping while and after writing, involuntary twitches of the finger, thigh and forearm muscles, foot drop-associated gait problems, hand weakness, hyporeflexia, and tongue percussion, his younger sister wasnt as affected as his brother, she only shared some of his symptoms, these include; upper and lower distal muscle weakness. Both siblings were revealed to have a chronic motor neuropathy, peripheral nerve fiber hyperexcitability, and multiple denervations. Muscle biopsies performed in the brother detected chronic partial denervation.Through the siblings reported by Hahn et al. and 50 new patients from 33 families across the world, it was found that this disorder is caused by HINT1 mutations. == References ==
It is also used off-label in the treatment of cyclical vomiting syndrome in infants; the only evidence for this use comes from retrospective studies.Cyproheptadine is sometimes used off-label to improve akathisia in people on antipsychotic medications.It is used off-label to treat various dermatological conditions, including psychogenic itch  drug-induced hyperhidrosis (excessive sweating), and prevention of blister formation for some people with epidermolysis bullosa simplex.One of the effects of the drug is increased appetite and weight gain, which has led to its use (off-label in the USA) for this purpose in children who are wasting as well as people with cystic fibrosis.It is also used off-label in the management of moderate to severe cases of serotonin syndrome, a complex of symptoms associated with the use of serotonergic drugs, such as selective serotonin reuptake inhibitors (and monoamine oxidase inhibitors), and in cases of high levels of serotonin in the blood resulting from a serotonin-producing carcinoid tumor.Cyproheptadine has sedative effects and can be used to treat insomnia similarly to other centrally-acting antihistamines. The recommended dose for this use is 4 to 8 mg. Adverse effects
Adverse effects include:

Overdose
Gastric decontamination measures such as activated charcoal are sometimes recommended in cases of overdose. The symptoms are usually indicative of CNS depression (or conversely CNS stimulation in some) and excess anticholinergic side effects. The LD50 in mice is 123 mg/kg and 295 mg/kg in rats. Pharmacology
Pharmacodynamics
Cyproheptadine is a very potent antihistamine or inverse agonist of the H1 receptor. At higher concentrations, it also has anticholinergic, antiserotonergic, and antidopaminergic activities.