A chimera may be intersex, composed of cells from a male twin and a female twin. In one case DNA tests determined that a woman, Lydia Fairchild, mystifyingly, was not the mother of two of her three children; she was found to be a chimera, and the two children were conceived from eggs derived from cells of their mothers twin. Parasitic twins
Sometimes one twin fetus will fail to develop completely and continue to cause problems for its surviving twin. One fetus acts as a parasite towards the other. Sometimes the parasitic twin becomes an almost indistinguishable part of the other, and sometimes this needs to be treated medically. Partial molar twins
A very rare type of parasitic twinning is one where a single viable twin is endangered when the other zygote becomes cancerous, or "molar". This means that the molar zygotes cellular division continues unchecked, resulting in a cancerous growth that overtakes the viable fetus. Typically, this results when one twin has either triploidy or complete paternal uniparental disomy, resulting in little or no fetus and a cancerous, overgrown placenta, resembling a bunch of grapes. Miscarried twin
Occasionally, a woman will suffer a miscarriage early in pregnancy, yet the pregnancy will continue; one twin was miscarried but the other was able to be carried to term. This occurrence is similar to the vanishing twin syndrome, but typically occurs later, as the twin is not reabsorbed. Low birth weight
It is very common for twins to be born at a low birth weight.
Benzonatate, sold under the brand name Tessalon among others, is a medication used to try to help with the symptoms of cough and hiccups. It is taken by mouth. Use is not recommended in those under the age of ten. Effects generally begin within 20 minutes and last up to eight hours.Side effects include sleepiness, dizziness, headache, upset stomach, skin rash, hallucinations, and allergic reactions. Excessive doses may cause seizures, irregular heartbeat, and death. Chewing or sucking on the capsule can lead to laryngospasm, bronchospasm, and circulatory collapse. It is unclear if use in pregnancy or breastfeeding is safe. It works by numbing stretch receptors in the lungs and suppressing the cough reflex in the brain.Benzonatate was approved for medical use in the United States in 1958. It is available as a generic medication. It is not available in many countries. In 2019, it was the 105th most commonly prescribed medication in the United States, with more than 6 million prescriptions. Medical uses
Cough
Benzonatate is a prescription non-opioid alternative for the symptomatic relief of cough. It has been shown to improve cough associated with a variety of respiratory conditions including asthma, bronchitis, pneumonia, tuberculosis, pneumothorax, opiate-resistant cough in lung cancer, and emphysema.Benzonatate also reduces the consistency and volume of sputum production associated with cough in those with chronic obstructive pulmonary disorder (COPD).Compared to codeine, benzonatate has been shown to be more effective in reducing the frequency of induced cough in experiments.Benzonatate does not treat the underlying cause of the cough.