Antitussives

Antitussives are drugs that suppress the cough reflex. They are used for dry irritable cough in which the elimination of the cough reflex prevents the accumulation of secretions. The most commonly used substances include dextromethorphan, codeine and its derivatives hydrocodone and dextramethorphan, the opium alkaloid noscapine, and pentoxyverine. Antitussives inhibit the cough reflex by an as yet unknown central mechanism. Peripheral effects are not involved in the antitussive action of these drugs.

Strong antitussives

• Codeine
• Dihydrocodeine
• Hydrocodone

Non-opioid antitussives

• Noscapine
• Pentoxyverine
• Dextromethorphan
• Benproperine
• Levodropropizine.

Phytotherapeutics (see below)

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Classification according to groups of active substances

Opioids Antitussives:

• Codeine
• Dihydrocodeine
• Ethylmorphine
• Hydrocodone
• Opium
• Pholcodine

NMDA antagonists (NMDA = N-methyl-D-aspartate) inhibit the cation channel of the NMDA receptor:

• Dextromethorphan

Benzylisoquinolines:

• Noscapine

Non-opioid antitussives:

• Dextromethorphan
• Butamirate
• Butetamate
• Levodropropizine
• Morclofon
• Benproperine
• Pentoxyverine

1st generation antihistamines:

• Diphenhydramine
• Oxomemazine
• Pheniramine
• Phenyltoloxamine

Herbal antitussives (phytotherapeutic antitussives, scientific evidence is mostly lacking):

• Marshmallow root/leaves(Altheae radix/folium): daily dose 6g roots/5g leaves
• Coltsfoot leaves(Farfarae folium) daily dose 5-6gdrug
• Icelandic moss(Lichen islandicus) daily dose 4-6g drug as infusion
• Lime leaves(Tiliae flos) Daily dose 4-6g
• Mallow leaves/flowers(Malvae folium/flos) Daily dose 5g drug
• Ribwort herb(Plantaginis lanceolatae herba) Daily dose 3-6g drug
• Large-flowered mullein/woolly flower(Verbasci flos) 3-4g drug
• Honey
• Sundew(Drosera herba) average daily dose 3.0-10.0g

The most important indication for antitussives is dry irritable cough, which can often occur in the context of viral infections of the respiratory tract but can also be caused by other organ diseases. In this case there is no secretion of inflammatory secretion (=unproductive cough). Antitussives may also be useful, for a limited time, in moderately productive coughs.

Remark: In principle, antitussives should only be used for a limited period of time and under strict indication.

Cough is an indispensable defensive reflex of the organism. Coughing is also a common symptom of diseases such as asthma, chronic obstructive pulmonary disease (COPD) and bronchial carcinoma (Morjaria JB et al. 2013).