What is Nyquil?
Nyquil is a popular over-the-counter, non-prescription medication for flu and common cold symptoms. It's available in various forms, including liquid capsules, pills, and syrup. Some of the ingredients discussed below make one feel sleepy, so it is often used at night to provide relief during this critical period of rest [1, 2].
What does Nyquil contain?
Nyquil's effectiveness and popularity stem from its combination of active ingredients. These include acetaminophen or paracetamol, a common pain reliever that targets headaches, minor aches, pains, fever, and sore throat symptoms. It also contains dextromethorphan, a substance that can suppress coughing [2].
Another key ingredient in Nyquil is doxylamine succinate. This antihistamine helps relieve sneezing, runny nose, and sinus congestion, similar to the activity of anti-allergy pills. However, it can also cause significant drowsiness, which can aid in sleep, but can impair coordination and mental alertness when taken during the day [2].
Some Nyquil products contain phenylephrine hydrochloride, a decongestant that relieves symptoms associated with sinus congestion, such as a runny nose. In contrast to doxylamine succinate, which also alleviates congestion, this ingredient does not cause sleepiness [2].
Although Nyquil is usually safe, there is a small risk of misuse when combined with certain medications or taking a dose that is too high. Misuse can lead to several risks, including difficulty breathing, increased urination, seizures, dizziness, hallucinations, dilated pupils, liver disease, and even death. Therefore, it's crucial to follow the recommended dosage and consult a healthcare professional if you have any concerns [3].
What is Diazepam?
Diazepam, also known by the brand name Valium, is a benzodiazepine medication [4, 5]. It is a central nervous system depressant, meaning it reduces brain activity by increasing the activity of the GABA neurotransmitter [5, 6].
What is diazepam used for?
Diazepam is primarily prescribed to relieve anxiety and alcohol withdrawal symptoms [4, 7]. It is also used with other medications to control muscle spasms caused by neurological disorders [4]. In addition, diazepam can be used to control seizures by calming the over-synchronized activity of neurons that occurs during a seizure [4].
Diazepam side effects
Despite its therapeutic benefits, diazepam can cause side effects such as impaired motor coordination, dizziness, and slurred speech [7].
If you take diazepam for a long time, you can develop a dependence on it, similar to substance use disorders. This is why diazepam is only used for shorter periods, and you must follow your healthcare provider's instructions regarding diazepam use [8].
Can You take Nyquil and Diazepam together?
NyQuil and Diazepam are both medications that can cause drowsiness as a side effect. NyQuil is an over-the-counter medication used to relieve symptoms of colds and the flu, while diazepam is a prescription medication used to treat anxiety, alcohol withdrawal, and seizures.
Diazepam and Nyquil both cause sedation
When considering the combination of these two drugs, it's important to remember that both have sedative effects., which can be enhanced by the drug combination. NyQuil contains an antihistamine called doxylamine succinate, which can cause drowsiness. Diazepam also has sedative effects by stimulating GABA receptors. Therefore, combining these two medications could lead to an increased level of sedation, which could be dangerous [2, 9].
Diazepam and Nyquil are metabolised in the liver
Moreover, NyQuil contains acetaminophen, a drug that can cause liver damage if used excessively or combined with alcohol. Diazepam, when combined with alcohol, doesn't show significant synergistic interactions, but in some cases, large supra-additive effects occurred, which were not explained by increased drug levels [10, 9]. There is some overlap between the breakdown of acetaminophen and diazepam in the liver, which could increase the half-life of these drugs in your system and increase the risk of side effects.
You should always consult a healthcare professional before taking new or combined medications. Older adults, people with preexisting medical conditions such as heart problems or high or low blood pressure, and pregnant or breastfeeding women are at higher risk if side effects do arise. People taking certain medicines, such as blood thinners or antihypertensive medication, are also at higher risk for possible interactions of these drugs with diazepam and Nyquil [2, 9].
Summary: Diazepam and Nyquil
To summarise, while there may not be a direct pharmacological interaction between NyQuil and Diazepam, the combination could potentially enhance sedative effects and increase the risk of liver damage. Therefore, consulting with a healthcare professional before taking these medications is recommended.