Pharmacology
Pharmacodynamics
Clozapine is classified as an atypical antipsychotic drug because it binds to serotonin as well as dopamine receptors.Clozapine is an antagonist at the 5-HT2A subunit of the serotonin receptor, putatively improving depression, anxiety, and the negative cognitive symptoms associated with schizophrenia.A direct interaction of clozapine with the GABAB receptor has also been shown. GABAB receptor-deficient mice exhibit increased extracellular dopamine levels and altered locomotor behaviour equivalent to that in schizophrenia animal models. GABAB receptor agonists and positive allosteric modulators reduce the locomotor changes in these models.Clozapine induces the release of glutamate and D-serine, an agonist at the glycine site of the NMDA receptor, from astrocytes, and reduces the expression of astrocytic glutamate transporters. These are direct effects that are also present in astrocyte cell cultures not containing neurons. Clozapine prevents impaired NMDA receptor expression caused by NMDA receptor antagonists. Pharmacokinetics
The absorption of clozapine is almost complete following oral administration, but the oral bioavailability is only 60 to 70% due to first-pass metabolism. The time to peak concentration after oral dosing is about 2.5 hours, and food does not appear to affect the bioavailability of clozapine. However, it was shown that co-administration of food decreases the rate of absorption. The elimination half-life of clozapine is about 14 hours at steady state conditions (varying with daily dose).Clozapine is extensively metabolized in the liver, via the cytochrome P450 system, to polar metabolites suitable for elimination in the urine and feces. The major metabolite, norclozapine (desmethyl-clozapine), is pharmacologically active.
Calcinosis cutis  is a type of calcinosis wherein calcium deposits form in the skin. A variety of factors can result in this condition. The most common source is dystrophic calcification, which occurs in soft tissue as a response to injury. In addition, calcinosis is seen in Limited Cutaneous Systemic Sclerosis, also known as CREST syndrome (the "C" in CREST). In dogs, calcinosis cutis is found in young, large breed dogs and is thought to occur after a traumatic injury. Causes
Calcinosis may result from a variety of causes such as:

Trauma to the region
Inflammation (bug bites, acne)
Varicose veins
Infections
Tumors (malignant or benign)
Diseases of connective tissue
Hypercalcemia
HyperphosphatemiaCalcinosis cutis is associated with systemic sclerosis. Diagnosis
Types
Calcinosis cutis may be divided into the following types:: 527–530 
Dystrophic calcinosis cutis
Metastatic calcinosis cutis
Iatrogenic calcinosis cutis
Traumatic calcinosis cutis
Idiopathic calcinosis cutis
Idiopathic scrotal calcinosis
Subepidermal calcified nodule
Tumoral calcinosis
Osteoma cutis

Treatment
Intralesional corticosteroids may be beneficial. Colchicine has been shown to be effective in certain populations. The efficacy of other treatments, such as magnesium or aluminum antacids, sodium etidronate, diphosphonates and diltiazem is unclear, but they have been reported to be serviceable in refractory calcinosis. Surgical options may be considered, particularly if there is associated ulceration. Gallery
See also
Calcinosis
List of cutaneous conditions

References


== External links ==