While the weather’s still warm, the fact that autumn’s around the corner means OTC cold and flu meds will soon be flying off the shelves again. With no cure to the common cold of flu, relieving symptoms is the focus of treatment. The key is recommending the correct medications for patients’ individual symptoms. Because with so many all-in-one products, patients are at risk of taking medicines that they do not need, and this can increase the likelihood of side effects. Here we take a closer look at decongestants, antitussives, expectorants, and analgesics.
Although mild when suffering from a cold, general aches and pains are common symptoms in patients suffering from the flu and can be quite severe. On occasion, a patient may suffer from a sore throat acute enough to benefit from a painkiller. The two most common analgesics found in cold and flu medications are paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs), in particular ibuprofen.
An analgesic (painkiller) is any member of the group of drugs used to achieve analgesia (relief from pain). “Paracetamol or ibuprofen can be helpful in relieving some cold symptoms such as fever, headache, ear pain, muscle, and joint pains,” said Dr Jorge Moreno, an internal medicine physician at Yale Medicine.
Oral tablet, capsule, syrup, drops, effervescent, and suppository.
MECHANISM OF ACTION
- Paracetamol: After more than 100 years, paracetamol’s exact mechanism of action is yet to be fully determined. According to Dr Chhaya Sharma al. in Volume 14 of Continuing Education in Anaesthesia Critical Care & Pain, “There is evidence for a number of central mechanisms, including effects on prostaglandin production, and on serotonergic, opioid, nitric oxide, and cannabinoid pathways, and it is likely that a combination of interrelated pathways are in fact involved.”
- Ibuprofen: Like other NSAIDs, ibuprofen works by blocking the production of prostaglandins – which cause inflammation – by decreasing the activity of the enzyme cyclooxygenase (COX).
- Paracetamol and ibuprofen are often mixed in with cold and flu medicines so make sure patients are aware of this to ensure they don’t take an additional analgesics.
- Paracetamol is a common analgesic and antipyretic drug for management of fever and mild-to-moderate pain in infants and children, and it is considered as first-line therapy for the treatment of both according to international guidelines and recommendations.
- When it comes to dosing, weight is more important than age, so encourage patients to always check the product label before giving medicine to their child
- While effective for the treatment of fever, paracetamol suppositories should be avoided in pain management.
A common cold and flu symptom, congestion is caused by swollen nasal passages. The swelling leads to increased mucus production, resulting in a runny nose.
Decongestants are used to relieve symptoms of nasal congestion commonly caused by cold and flu.
Nasal sprays and nose drops, oral tablets, capsules, drops, or syrups, and rubs.
MECHANISM OF ACTION
Dilated blood vessels in the nasal and airway membranes are what cause congestion in the nose, sinuses, and chest. Decongestants work by narrowing those blood vessels, decreasing swelling and inflammation and the associated mucus production.
- Most manufacturers warn that decongestant nasal sprays should not be used longer than five days. Prolonged use can cause rebound congestion (rhinitis medicamentosa) – congestion caused by medication.
- Common decongestants include phenylephrine, pseudoephedrine, and oxymetazoline.
- Decongestant nasal sprays have an immediate effect to clear a blocked nose. Oral tablets and capsules may take a little longer to work because they need to be absorbed into the body.
- Many medicines combine a decongestant and antihistamine. Some combination medicines contain a decongestant and analgesic.
- As an antibacterial, natural decongestant, eucalyptus often reduces the intensity and the duration of respiratory illnesses.
Cough is one of the most common complaints during cold and flu season. Professor of respiratory medicine at Royal Brompton Hospital, Professor Kian Fan Chung describes cough as “an essential innate protective mechanism that ensures the removal of mucus, noxious substances, and infections from the larynx, trachea, and large bronchi.”
Oral tablets and syrups, topical rubs, or are inhaled through a vaporiser.
MECHANISM OF ACTION
In Applied Pharmacology, Dr Stan Bardal, Dr Jason Waechter, and Dr Doug Martin explain that antitussives inhibit cough through either a central or a peripheral mechanism, or a mixture of the two.
- Central mechanism: Common centrally acting agents include dextromethorphan, codeine, hydrocodone, pholcodine, and baclofen. In Pharmacology and Therapeutics of Cough, Professor Donald Bolser stated it is widely accepted that centrally acting antitussive drugs work by inhibiting the cough centre in the brain, elevating the threshold for coughing. While one study found pholcodine had significantly better tolerability than dextromethorphan, the authors also reported that the use of pholcodine may also be considered a safe option for paediatric use.
- Peripheral mechanism: Common peripherally acting agents include camphor, menthol, eucalyptus oil, benzonatate, and levodropropizine. “Peripheral-acting agents work either by anesthetising the local nerve endings or acting as demulcents,” said Dr Bardal al. “Demulcents have a soothing effect on the throat.”
- Most cough medications are combinations of antitussives, expectorants, mucolytics, bronchodilators, and sedatives.
- Dextromethorphan has an onset of action of 15-30 minutes and a duration of 3-6 hours.
Expectorants increase secretion of mucins and are defined as drugs that induce discharge or expulsion of mucus from the respiratory tract.
Expectorants are indicated for the management of acute respiratory tract infections like the common cold and flu.
Oral tablets, capsules, syrup, drops, and effervescent.
MECHANISM OF ACTION
Expectorants break up congestion in the chest by thinning the mucus in the respiratory tract. This makes it easier for patients to cough up phlegm more easily. The most commonly available OTC expectorant, guaifenesin works by drawing water into the bronchi (the passageways that allow air into the lungs), which thins the mucous trapped there and loosens it, allowing it to be coughed up more easily.
- Available as a standalone drug, expectorants are also commonly found in combination OTC cough, cold, and flu medicines.
- You can recommend an expectorant to a patient with a productive cough, but a dry or tickly cough usually requires a cough suppressant.
There are several effective herbal preparations to treat cold and flu symptoms, many of which are made up of several natural ingredients. “Herbs such as Andrographis, Echinacea and berberine-containing plants can help reduce the duration and severity of the flu,” said Dr Amanda Reimann (Medical Herbalist & Biochemist at ATUNE Health Centres). “They have anti-viral as well as immune supporting activities. Herbs can also help to soothe a sore throat and encourage the production of mucus. This will help to relieve the symptoms of the flu.”
- Marshmallow (Althaea officinalis): According to authors of Cough Suppressant Herbal Drugs: A Review published in the International Journal of Pharmaceutical Science Invention, the leaves and roots of the herb have been used since ancient times to treat sore throats and coughs. “The marshmallow herb contains mucilage, which coats the throat and soothes irritation,” said Dr Shahnaz Sultana et al.
- Thyme (Thymus vulgaris): Said to possess expectorant, mucolytic, antitussive, and antispasmodic properties, thyme is a common ingredient in combination cold and flu preparations. According to pharmacognosist Prof Michael Balick the herb eases coughs and bronchial spasms and helps clear congestion and mucus. Dr Amanda Reimann (Medical Herbalist & Biochemist at ATUNE Health Centres) credits the herbs inclusion in many cough syrups to its effectiveness as a cough suppressant.
- Echinacea (Echinacea purpurea): One of the most widely used herbs to treat influenza, Dr Reimann explains that echinacea acts on the immune system by stimulating and modulating it and it has anti-viral and antibacterial properties. , Dr Reimann explains. “Overall, clinical studies support the use of Echinacea in preventing the common cold and to relieve upper respiratory tract infections.”
- Elderberry (Sambucus canadensis): Thought to have antioxidant and immune-modulating properties, there is evidence to suggest that elderberry does reduce symptoms of the flu.
- Pelargonium Sidoides: “Extracts of Pelargonium have been promoted for a variety of respiratory conditions, including bronchitis, sinusitis, tonsillopharyngitis, otitis media, and the common cold,” Cathleen Murphy and colleagues reported in Sorting Out Supplements for the Common Cold published in US Pharmacist. “In one trial, the authors concluded that this herbal significantly reduces the duration of a cold and ameliorates the severity of cold symptoms,” said Murphy et al.