The drug noscapine is extracted from the opium poppy. It finds application in the relief of cough irritation.
What is noscapine?
The drug noscapine is extracted from the opium poppy. It finds use in the relief of cough irritation. Noscapine is an antitussive. This means that the active ingredient is used to treat cough. The alkaloid noscapine is obtained from the opium poppy (Papaver somniferum), which belongs to the poppy family (Papaveraceae) and from which opium can also be produced. Noscapine was already known to the French pharmacist and chemist Antoine Baume (1728-1804) as an opium extract. In 1817, his compatriot Pierre-Jean Robiquet (1780-1840) succeeded in isolating the active ingredient from opium. From a chemical point of view, the substance is a methoxy derivative of the alkaloid hydrastine. In Germany, noscapine is offered as a monopreparation under the name Capval.
Pharmacological action
Noscapine belongs to the group of antitussives, also called cough suppressants. Antitussives have the property of inhibiting the cough center, which is located within the brainstem. The same applies to the sensitive receptors of the lungs. However, the use of antitussives such as noscapine only makes sense if the cough is a dry cough without mucus secretion. This is because inhibiting the cough center prevents the mucus from being coughed up, which can possibly result in the infection worsening. Noscapine exerts its effect exclusively peripherally. Thus, the substance has bronchodilator and respiratory stimulant effects. However, because noscapine has no analgesic properties, it does not belong to the opiates. In addition, it does not induce euphoric effects, so there is no addictive potential. Because of its peripheral action properties, noscapine cannot suppress breathing or have a sedative effect. Another advantage of the drug is that it does not produce the side effect of constipation often associated with opioid use. According to recent studies, noscapine also has the virtue of inhibiting the CYP2C9 enzyme, which gives the drug antitumor effects. The plasma half-life of noscapine ranges from 2.6 to 4.5 hours. In this way, there is an individually variable bioavailability, which is approximately 30 percent.
Medical application and use
Noscapine is used to treat nonproductive nocturnal irritable cough. This refers to cough without mucus. The cough is not a disease in its own right, but is caused by certain causes. These may be acute or chronic bronchitis, chronic obstructive pulmonary disease (COPD) or whooping cough (pertussis). Sometimes anatomical changes or tumors are also responsible for the development of an irritable cough. Noscapine is also considered useful if the cough causes significant stress on the heart and circulation. This includes, for example, the risk of an aneurysm bursting due to the intense coughing. Noscapine is taken orally in the form of coated tablets or juice. The common dose for children 6 to 12 years of age is three lozenges a day, while children over 12 years of age and adults take 2 lozenges three times a day. For babies over six months and toddlers up to five years of age, other dosage forms such as juice or drops are available that are more suitable for them. Noscapine lozenges usually have 25 milligrams of noscapine in each. The juice contains 25 milligrams of noscapine in 5 grams. In adults, cough suppression is achieved with a dosage of 50 to 100 milligrams of noscapine. How long the antitussive must be taken depends on the course of the disease. Since noscapine is subject to prescription in Germany, the drug is available in this country only on presentation of a prescription in the pharmacy.
Risks and side effects
Adverse side effects are rarely seen when taking noscapine. The most common are drowsiness and headache. In some cases, itching, skin reactions, and dizziness may also occur. Rarely, Quincke’s edema occurs in the face and neck region, manifested by swelling. Other conceivable side effects include pain in the upper abdomen, shortness of breath, and a feeling of anxiety. If the dose of noscapine is too high, there is a risk of seizures.Noscapine must not be taken if the patient is hypersensitive to the drug. The same applies to an allergy to components of the antitussive such as methyl hydroxybenzoate. It is not advisable to administer noscapine in cases of pronounced mucus formation. Thus, the coughing up of mucus is prevented by the active ingredient. The administration of Noscapine is not suitable for children younger than six months. Noscapine should also not be taken during the first trimester of pregnancy. Thus, a possible miscarriage cannot be clearly excluded by the antitussive. During breastfeeding, on the other hand, there are no objections to the administration of the cough suppressant, since only small amounts pass into breast milk, so that the baby is not at risk. After taking noscapine, the patient should refrain from driving cars or other motor vehicles. The same applies to the operation of complicated machines or electric tools, since the drug can negatively affect the ability to react. In addition, interactions between noscapine and other medications are possible. It is therefore advisable not to administer the antitussive together with mucolytic preparations, as there is otherwise a risk of secretion build-up. Likewise, it is not advisable to administer it together with opioids, sleeping pills, neuroleptics, antidepressants, sedatives, and alcohol.
