Some or all oral estradiol valerate tablets are micronized, similarly to oral estradiol tablets.In addition to single-drug formulations, oral estradiol valerate is available in combination with the progestin dienogest as a combined oral contraceptive and intramuscular estradiol valerate is marketed at a concentration of 5 mg/mL in combination with the progestin hydroxyprogesterone caproate and with the progestin norethisterone enantate as combined injectable contraceptives. Intramuscular estradiol valerate is also marketed at a concentration of 4 mg/mL in combination with the weak androgen and neurosteroid prasterone enanthate (DHEA enanthate) and with the androgen testosterone enantate for use in menopausal hormone therapy, but the latter formulation has been discontinued. The availability of estradiol valerate-containing products varies throughout the world. Contraindications
Contraindications of estrogens include coagulation problems, cardiovascular diseases, liver disease, and certain hormone-sensitive cancers such as breast cancer and endometrial cancer, among others. Side effects
The side effects of estradiol valerate are the same as those of estradiol. Examples of such side effects include breast tenderness and enlargement, nausea, bloating, edema, headache, and melasma. High-dose estrogen therapy with estradiol valerate injections may also cause an increased risk of thromboembolism, changes in blood lipid profile, increased insulin resistance, and increased levels of prolactin. Overdose
Estradiol valerate has been used at very high doses of 40 to 100 mg once per week in women and men, without overt signs of acute toxicity observed. Symptoms of estrogen overdosage may include nausea, vomiting, bloating, increased weight, water retention, breast tenderness, vaginal discharge, heavy legs, and leg cramps.
It is a rare extrapyramidal side effect of phenothiazines, haloperidol, and metoclopramide.Opisthotonus with the presence of the risus sardonicus is also a symptom of strychnine poisoning and prussic acid (hydrogen cyanide) poisoning. Drowning and the "dinosaur death pose"
Opisthotonus is seen with drowning victims – called the "opisthotonic death pose". This pose is also common in complete dinosaur skeletal fossils and it has been suggested that this is due to the animal drowning or being immersed in water soon after death. Vivisection
Opisthotonus can be produced experimentally in animals by transection of the midbrain (between the superior colliculus and the inferior colliculus), which results in severing all the corticoreticular fibers.Severe "arching" (hyperextension) occurs due to stimulus by the anterior reticulospinal tract caused by the loss of the balancing inhibitory counter-stimulus of corticoreticular fibers, which normally act upon the pons reticular formation. Other causes
Opisthotonus is also described as a potential CNS symptom of heat stroke along with bizarre behavior, hallucinations, decerebrate rigidity, oculogyric crisis, and cerebellar dysfunction.Opisthotonus is a symptom of "lavender foal syndrome", a lethal genetic disorder in horses.Sir Rudolph Peters, in Oxford, introduced thiamine-deprived pigeons as a model for understanding how thiamine deficiency can lead to the pathological-physiological symptoms of beriberi. Indeed, feeding the pigeons upon polished rice leads to an easily recognizable behavior of head retraction, a condition called opisthotonos. If not treated, the animals died after a few days. Administration of thiamine at the stage of opisthotonos led to a complete cure within 30 minutes.