Levels of fulvestrant with 500 mg/month by intramuscular injection (and a single additional 500 mg loading dose on day 15 of therapy) in postmenopausal women with advanced breast cancer were 25.1 ng/mL (25,100 pg/mL) at peak and 28.0 ng/mL (28,000 pg/mL) at trough with a single dose and 28.0 ng/mL (28,000 pg/mL) at peak and 12.2 ng/mL (12,200 pg/mL) at trough after multiple doses at steady state.Fulvestrant does not cross the blood–brain barrier in animals and may not in humans as well. Accordingly, no effects of fulvestrant on brain function have been observed in preclinical or clinical research. Fulvestrant is highly (99%) bound to plasma proteins. It is bound to very low density lipoprotein, low density lipoprotein, and high density lipoprotein, but not to sex hormone-binding globulin.Fulvestrant appears to be metabolized along similar pathways as endogenous steroids; CYP3A4 may be involved, but non-cytochrome P450 routes appear to be more important. It does not inhibit any cytochrome P450 enzymes. Elimination is almost all via feces.Fulvestrant can form colloidal aggregates at certain concentration ranges and this can limit its activity as well as produce bell-shaped concentration–response curves. Chemistry
Fulvestrant, also known as 7α-[9-[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estradiol, is a synthetic estrane steroid and a derivative of estradiol. An alkyl-sulfinyl moiety was added to the endogenous estrogen receptor ligand.It was discovered through rational drug design, but was selected for further development via phenotypic screening. History
Fulvestrant was the first selective estrogen receptor degrader to be approved. It was approved in the United States in 2002 and in Europe in 2004.
sinus tachycardia
Orthostatic hypotension
Hypotension
Swollen tongue
Dysphagia (difficulty swallowing)
Glossodynia
Oral paraesthesiaRare (0.01-0.1% incidence) adverse effects include:

Neuroleptic malignant syndrome (Combination of fever, muscle stiffness, faster breathing, sweating, reduced consciousness, and sudden change in blood pressure and heart rate)
Tardive dyskinesia
Speech disturbance
Rhabdomyolysis
Angioedema
Blood dyscrasias such as agranulocytosis, leukopenia and neutropenia
Accommodation disorder
Pulmonary embolism
Gynaecomastia
GalactorrhoeaUnknown incidence adverse effects

Allergic reaction
Restless legs syndrome
Nausea
Oral mucosal lesions (ulcerations, blistering and inflammation)
Salivary hypersecretion
HyperprolactinaemiaAsenapine seems to have a relatively low weight gain liability for an atypical antipsychotic (which are notorious for their metabolic side effects) and a 2013 meta-analysis found significantly less weight gain (SMD [standard mean difference in weight gained in those on placebo vs. active drug]: 0.23; 95% CI: 0.07-0.39) than, paliperidone (SMD: 0.38; 95% CI: 0.27-0.48), risperidone (SMD: 0.42; 95% CI: 0.33-0.50), quetiapine (SMD: 0.43; 95% CI: 0.34-0.53), sertindole (SMD: 0.53; 95% CI: 0.38-0.68), chlorpromazine (SMD: 0.55; 95% CI: 0.34-0.76), iloperidone (SMD: 0.62; 95% CI: 0.49-0.74), clozapine (SMD: 0.65; 95% CI: 0.31-0.99), zotepine (SMD: 0.71; 95% CI: 0.47-0.96) and olanzapine (SMD: 0.74; 95% CI: 0.67-0.81) and approximately (that is, no statistically significant difference at the p=0.05 level) as much as weight gain as aripiprazole (SMD: 0.17; 95% CI: 0.05-0.28), lurasidone (SMD: 0.10; 95% CI: –0.02-0.21), amisulpride (SMD: 0.20; 95% CI: 0.05-0.35), haloperidol (SMD: 0.09; 95% CI: 0.00-0.17) and ziprasidone (SMD: 0.10; 95% CI: –0.02-0.22). Its potential for elevating plasma prolactin levels seems relatively limited too according to this meta-analysis.