It is assumed, though not yet proven, that decrease in KV1.1 mediated current leads to prolonged action potentials in interneurons and basket cells. As these channels are important in the regulation of Purkinje cell activity, it is likely that this results increased and aberrant inhibitory input into Purkinje cells and, thus, disrupted Purkinje cell firing and cerebellum output. EA2: CACNA1A
Type 2 episodic ataxia (EA2) is characterized by acetazolamide-responsive attacks of ataxia with or without migraine. Patients with EA2 may also present with progressive cerebellar atrophy, nystagmus, vertigo, visual disturbances and dysarthria. These symptoms last from hours to days, in contrast with EA1, which lasts from seconds to minutes. Attacks can be accompanied by increased heart rate and blood pressure, moderate to severe shaking, and stuttering. Like EA1, attacks can be precipitated by exercise, emotional stress/agitation, physical stress, or heat (overheated body temperature) but also by coffee and alcohol. EA2 is caused by mutations in CACNA1A, which encodes the P/Q-type voltage-gated calcium channel CaV2.1, and is also the gene responsible for causing spinocerebellar ataxia type-6 and familial hemiplegic migraine type-1. EA2 is also referred to as episodic ataxia with nystagmus, hereditary paroxysmal cerebellopathy, familial paroxysmal ataxia and acetazolamide-responsive hereditary paroxysmal cerebellar ataxia (AHPCA). There are currently 19 mutations associated with EA2, though only 3 have been characterized electrophysiologically, table 2 and figure 2. Of these, all result in decreased current through these channels.
Side effects
Liothyronine may cause a number of side effects, mostly similar to symptoms of hyperthyroidism, which include:
weight loss
tremor
headache
upset stomach
vomiting
diarrhea
stomach cramps
nervousness
irritability
insomnia
excessive sweating
increased appetite
fever
changes in menstrual cycle
sensitivity to heat

Boxed warning
The package insert contains the following boxed warning, as do all thyroid hormones:

Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects. Pharmacology
Liothyronine is the most potent form of thyroid hormone. As a salt of triiodothyronine (T3), it is chemically similar and pharmacologically equivalent to T3. As such, it acts on the body to increase the basal metabolic rate, affect protein synthesis and increase the bodys sensitivity to catecholamines (such as adrenaline) by permissiveness. As monotherapy or in combination therapy with SSRIs, liothyronine may also enhance generation of new neurons in the central nervous system. The thyroid hormones are essential to proper development and differentiation of all cells of the human body. These hormones also regulate protein, fat, and carbohydrate metabolism, affecting how human cells use energetic compounds. In comparison to levothyroxine (T4), liothyronine has a faster onset of action as well as a shorter biological half-life, which may be due to less plasma protein binding to thyroxine-binding globulin and transthyretin.