As harmful noise exposure continues, the commonly affected frequencies will broaden to lower frequencies and worsen in severity. Prevention
NIHL can be prevented through the use of simple, widely available, and economical tools. This includes but is not limited to personal noise reduction through the use of ear protection (i.e. earplugs and earmuffs), education, and hearing conservation programs. For the average person, there are three basic things that one can do to prevent NIHL: turn down the volume on devices, move away from the source of noise, and wear hearing protectors in loud environments.Non-occupational noise exposure is not regulated or governed in the same manner as occupational noise exposure; therefore prevention efforts rely heavily on education awareness campaigns and public policy. The WHO cites that nearly half of those affected by hearing loss could have been prevented through primary prevention efforts such as: "reducing exposure (both occupational and recreational) to loud sounds by raising awareness about the risks; developing and enforcing relevant legislation; and encouraging individuals to use personal protective devices such as earplugs and noise-cancelling earphones and headphones." Personal noise reduction devices
Personal noise reduction devices can be passive, active or a combination. Passive ear protection includes earplugs or earmuffs which can block noise up to a specific frequency. Earplugs and earmuffs can provide the wearer with 10 dB to 40 dB of attenuation. However, use of earplugs is only effective if the users have been educated and use them properly; without proper use, protection falls far below manufacturer ratings.
In 2020, it was the sixth most commonly prescribed medication in the United States, with more than 66 million prescriptions. Medical uses
Metoprolol is used for a number of conditions, including hypertension, angina, acute myocardial infarction, supraventricular tachycardia, ventricular tachycardia, congestive heart failure, and prevention of migraine headaches. It is an adjunct in the treatment of hyperthyroidism.The different salt versions of metoprolol – metoprolol tartrate and metoprolol succinate – are approved for different conditions and are not interchangeable.Off-label uses include supraventricular tachycardia and thyroid storm. Available forms
Metoprolol is sold in formulations that can be taken by mouth or given intravenously. The medication is often taken twice a day. The extended-release formulation is taken once a day. Metoprolol may be combined with hydrochlorothiazide (a diuretic) in a single tablet. Adverse effects
Adverse effects, especially with higher doses, include dizziness, drowsiness, fatigue, diarrhea, unusual dreams, trouble sleeping, depression, and vision problems. β-blockers, including metoprolol, reduce salivary flow via inhibition of the direct sympathetic innervation of the salivary glands. Metoprolol may also cause the hands and feet to feel cold.