A dextromethorphan overdose is a potentially serious situation. Prompt medical attention should be sought if it is suspected that there has been an overdose, even if symptoms, such as changes in consciousness, cardiopulmonary activity, or uncontrolled muscular contractions, are not yet present. The more quickly a person is brought in for treatment, the better his or her chances of survival and of complete recovery with no lingering effects.
One of the most serious signs of a dextromethorphan overdose is the loss of consciousness. If a person loses consciousness after taking too much of this medication, paramedics should be alerted so that the person can be put on life support as soon as possible and brought to a hospital. It is possible for a person to experience respiratory distress while unconscious, which can lead to death. The heart can also stop beating as a result of a dextromethorphan overdose, and this can happen while a person is unconscious or as a precursor to a loss of consciousness. The unconscious person should be monitored for signs of respiratory distress, and cardiopulmonary resuscitation (CPR) should be given as needed.
Aside from these extremely serious symptoms, there are a number of other symptoms that could indicate a dextromethorphan overdose. Psychological effects such as confusion, drowsiness, or hallucinations are not uncommon. A person may also become dizzy and disoriented and may have difficulty focusing either because of the disorientation or because of blurred vision.
Cardiopulmonary symptoms are also common with a dextromethorphan overdose. While in extreme cases, this may mean that the person stops breathing altogether or that the heart ceases to beat, there are a number of other symptoms that are less noticeable that can indicate distress. The breathing may slow or become labored, and the fingers and fingernails may take on a bluish tint, which is more noticeable in people with fair skin. This bluish tint is an indicator that not enough oxygen is reaching the extremities. The heart may also beat very quickly, the blood pressure may either rise or fall, and the person may run a fever.
Uncontrolled muscle movements are also a common feature of a dextromethorphan overdose. These can occur all over the body and may appear as small muscular twitches or as full-body convulsions. Internally, the rapid contraction of muscles can cause spasms in the digestive tract, causing a great deal of pain and discomfort and resulting in vomiting.