Side effects
Some common side effects such as drowsiness, dry mouth, and tiredness may occur. Meclizine has been shown to have fewer dry mouth side effects than the traditional treatment for motion sickness, transdermal scopolamine. A very serious allergic reaction to this drug is unlikely, but immediate medical attention should be sought if it occurs. Symptoms of a serious allergic reaction may include rash, itching, swelling, severe dizziness, and trouble breathing. Drowsiness
Drowsiness may result as a side effect of taking meclizine. Users are advised not to operate heavy machinery while under the influence. The consumption of alcohol while under the influence of meclizine may result in additional drowsiness. Elderly
As with any anticholinergic agent, meclizine may cause confusion or aggravate symptoms in those with dementia in the geriatric population (older than 65 years). Therefore, caution should be used when administering meclizine to the elderly. Mechanism of action
Meclizine is an antagonist at H1 receptors. It possesses anticholinergic, central nervous system depressant, and local anesthetic effects. Its antiemetic and antivertigo effects are not fully understood, but its central anticholinergic properties are partially responsible. The drug depresses labyrinth excitability and vestibular stimulation, and it may affect the medullary chemoreceptor trigger zone. It has however been suggested that meclizine only has an inhibitory effect under normal viewing-circumstances, as the drug has been shown to enhance an isolated vestibular response. Much like motion-sickness arises from a discrepancy between multiple senses, Meclizine most likely affects a wide array of sensory mechanisms related to self-motion.
Fat is then gradually lost in is the limbs and trunk. Fat may accumulate around the face and between the shoulder blades. Insulin resistance is common. Other conditions associated with this condition include acanthosis nigricans, fatty liver, hypertriglyceridemia and polycystic ovary syndrome in women. There is an increased risk of coronary heart disease. Cardiomyopathy and muscular dystrophy may occur rarely. Xanthoma and nail changes may occur. Type 3 is due to mutations in the PPARG gene. It is rare with approximately 30 cases reported to date. It is similar to type 2 but tends to be milder. Type 4 is due to mutations in the PLIN1 gene. It is rare with only a small number of cases reported. Fat loss tends to affect the lower limbs and buttocks. Insulin resistance and hypertriglyceridemia occur. Calf muscular hypertrophy may occur. Type 5 is due to mutations in the AKT2 gene. It has been reported in four patients all members of the same family. Fat loss affects the upper and lower limbs. The patients also had hypertension, insulin resistance and hypertriglyceridemia. Type 6 due to mutations in the  CIDEC gene. It is inherited in an autosomal recessive fashion and has been reported in only one patient to date. Features included  fat loss, severe insulin resistance, fatty liver, acanthosis nigricans and diabetes. Another gene that has been associated with this condition is AGPAT2. Diagnosis
Treatment
Prevalence
This not known with certainty but is estimated to be about one per million. It appears to be more common in females than males.