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Timolol
open-in-new
<h2 id="medical-uses">Medical uses</h2> <h3>By mouth</h3> <p>In its by mouth or oral form, it is used: </p> <ul><li>to treat <a href="/facts/Hypertension/wlAvBfcf">high blood pressure</a></li> <li>to prevent <a href="/facts/Myocardial_infarction/xoGw0qcG">heart attacks</a></li> <li>to prevent <a href="/facts/Migraine/5XaE1W25">migraine</a> headaches<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a></li></ul> <p>The combination of timolol and the <a href="/facts/Alpha-1_blocker/IFz841Cn">alpha-1 blocker</a> <a href="/facts/Prazosin/VNdynKaL">prazosin</a> has <a href="/facts/Sedation/wFWEChs8">sedative</a> effects.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> </p> <h3>Eye drops</h3> <p>In its eye drop form it is used to treat open-angle and, occasionally, <a href="/facts/Secondary_glaucoma/Th8K4Yvd">secondary glaucoma</a>.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a><a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> The mechanism of action of timolol is probably the reduction of the formation of aqueous humor<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> in the ciliary body in the eye. It was the first <a href="/facts/Beta_blocker/PRsWgpLV">beta blocker</a> approved for topical use in treatment of glaucoma in the United States (1978).<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> When used by itself, it depresses <a href="/facts/Intraocular_pressure/VVnweTza">intraocular pressure</a> (IOP) 18–34% below baseline within first few treatments. However, there are short-term escape and long-term drift effects in some people. That is, tolerance develops. It may reduce the extent of the daytime IOP curve up to 50%. The IOP is higher during sleep. Efficacy of timolol in lowering IOP during the sleep period may be limited.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a><a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a><a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a> It is a 5–10× more potent beta blocker than <a href="/facts/Propranolol/QvH2XYt1">propranolol</a>. Timolol is light-sensitive; it is usually preserved with 0.01% <a href="/facts/Benzalkonium_chloride/BMg8MMAy">benzalkonium chloride</a> (BAC), but also comes BAC-free. It can also be used in combination with <a href="/facts/Pilocarpine/dVnhPSWP">pilocarpine</a>, <a href="/facts/Carbonic_anhydrase_inhibitor/NaX2lplt">carbonic anhydrase inhibitors</a><a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> or <a href="/facts/Prostaglandin/kIKw0gDj">prostaglandin</a> analogs.<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> </p><p>A <a href="/facts/Cochrane_Collaboration/UlmdJ1H8">Cochrane review</a> compared the effect of timolol versus <a href="/facts/Brimonidine/oYXMh7SE">brimonidine</a> in slowing the progression of open angle glaucoma in adults but found insufficient evidence to come to conclusions.<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> </p> <h3>On the skin</h3> <p>In its gel form it is used on the skin to treat <a href="/facts/Infantile_hemangiomas/oT89IbbQ">infantile hemangiomas</a>.<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> </p> <h2 id="contraindications">Contraindications</h2> <p>The medication should not be taken by individuals with:<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a> </p> <ul><li>An allergy to timolol or any other beta-blockers</li> <li><a href="/facts/Asthma/7GkJvxn3">Asthma</a> or <a href="/facts/Bronchitis/IATP1XWJ">severe chronic obstructive bronchitis</a></li> <li>A <a href="/facts/Bradycardia/70msP5HD">slow heart rate (bradycardia)</a>, or a <a href="/facts/Heart_block/ehuFjb1H">heart block</a></li> <li><a href="/facts/Heart_failure/7fckX3Jm">Heart failure</a><a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a></li></ul> <h2 id="side-effects">Side effects</h2> <p>The most serious possible side effects include cardiac <a href="/facts/Heart_arrhythmia/ooEpr46Q">arrhythmias</a> and severe <a href="/facts/Bronchospasm/E61Q1mGD">bronchospasms</a>.<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> Timolol can also lead to <a href="/facts/Syncope_(medicine)/AqU1whYh">fainting</a>, <a href="/facts/Heart_failure/7fckX3Jm">congestive heart failure</a>, <a href="/facts/Major_depressive_disorder/l2lQeWqr">depression</a>, <a href="/facts/Confusion/Pcvw6deb">confusion</a>, worsening of <a href="/facts/Raynaud%27s_syndrome/VorWr74H">Raynaud's syndrome</a> and <a href="/facts/Erectile_dysfunction/7HDetsos">impotence</a>.<a class="footnote-ref" id="fnref:33" href="#fn:33"><sup>33</sup></a> </p><p>Side effects when given in the eye include: burning sensation, eye redness, superficial punctate keratopathy, corneal numbness.<a class="footnote-ref" id="fnref:34" href="#fn:34"><sup>34</sup></a><a class="footnote-ref" id="fnref:35" href="#fn:35"><sup>35</sup></a> </p> <h2 id="formulations">Formulations</h2> <p>It is available in tablet and liquid formulations.<a class="footnote-ref" id="fnref:36" href="#fn:36"><sup>36</sup></a><a class="footnote-ref" id="fnref:37" href="#fn:37"><sup>37</sup></a> </p><p>For ophthalmic use, timolol is also available combined: </p> <ul><li>with <a href="/facts/Carbonic_anhydrase_inhibitor/NaX2lplt">carbonic anhydrase inhibitors</a>: <ul><li>timolol and <a href="/facts/Brinzolamide/Hbs2Q4DV">brinzolamide</a></li> <li><a href="/facts/Dorzolamide/timolol/4vHaJCCR">timolol and dorzolamide</a></li></ul></li> <li>with <a href="/facts/Alpha-2_adrenergic_receptor/QmUrvvYn">α2</a> agonists: <ul><li><a href="/facts/Brimonidine/timolol/PPL1eQGt">timolol and brimonidine</a></li></ul></li> <li>with <a href="/facts/Prostaglandin_analogue/P9UgPCP4">prostaglandin analogs</a>: <ul><li><a href="/facts/Latanoprost/timolol/RKIJ2HLW">timolol and latanoprost</a></li> <li>timolol and <a href="/facts/Travoprost/pP8MEVRm">travoprost</a></li></ul></li></ul> <h2 id="brand-names">Brand names</h2> <p>Timolol is sold under many <a href="/facts/Brand_name/hP6SnDWU">brand names</a> worldwide.<a class="footnote-ref" id="fnref:38" href="#fn:38"><sup>38</sup></a> Timolol eye drops are sold under the brand names Timoptic and Istalol among others.<a class="footnote-ref" id="fnref:39" href="#fn:39"><sup>39</sup></a><a class="footnote-ref" id="fnref:40" href="#fn:40"><sup>40</sup></a> </p> <h2 id="external-links">External links</h2> <ul><li><a href="https://medlineplus.gov/druginfo/meds/a682043.html">"Timolol Ophthalmic"</a>. <i>MedlinePlus</i>.</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Timolol eent". The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016. Retrieved 8 December 2016. <a href="https://www.drugs.com/monograph/timolol-eent.html" target="_blank">https://www.drugs.com/monograph/timolol-eent.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Timolol Maleate". The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016. Retrieved 8 December 2016. <a href="https://www.drugs.com/monograph/timolol-maleate.html" target="_blank">https://www.drugs.com/monograph/timolol-maleate.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"Timolol eent". The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016. Retrieved 8 December 2016. <a href="https://www.drugs.com/monograph/timolol-eent.html" target="_blank">https://www.drugs.com/monograph/timolol-eent.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>"Timolol Maleate". The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016. Retrieved 8 December 2016. <a href="https://www.drugs.com/monograph/timolol-maleate.html" target="_blank">https://www.drugs.com/monograph/timolol-maleate.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"Timolol eent". The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016. Retrieved 8 December 2016. <a href="https://www.drugs.com/monograph/timolol-eent.html" target="_blank">https://www.drugs.com/monograph/timolol-eent.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"Timolol Maleate". 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Retrieved 31 December 2019. <a href="https://medlineplus.gov/druginfo/meds/a682043.html" target="_blank">https://medlineplus.gov/druginfo/meds/a682043.html</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></p></li> <li id="fn:36"><p>"Timolol Maleate tablet". DailyMed. 17 August 2006. Retrieved 1 December 2019. <a href="https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=57c62928-63d8-4505-9b9e-c085a3a12c95" target="_blank">https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=57c62928-63d8-4505-9b9e-c085a3a12c95</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></p></li> <li id="fn:37"><p>"Betimol- timolol solution". DailyMed. 18 March 2010. Retrieved 1 December 2019. <a href="https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=00f62dd1-dad2-4892-8a5d-21e5e54509ce" target="_blank">https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=00f62dd1-dad2-4892-8a5d-21e5e54509ce</a> <a href="#fnref:37" class="footnote-back-ref">↩</a></p></li> <li id="fn:38"><p>"Timolol". Drugs.com. Archived from the original on 7 March 2016. Retrieved 28 December 2016. <a href="https://www.drugs.com/international/timolol.html" target="_blank">https://www.drugs.com/international/timolol.html</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></p></li> <li id="fn:39"><p>"Generic Istalol Availability". Drugs.com. Retrieved 20 June 2019. <a href="https://www.drugs.com/availability/generic-istalol.html" target="_blank">https://www.drugs.com/availability/generic-istalol.html</a> <a href="#fnref:39" class="footnote-back-ref">↩</a></p></li> <li id="fn:40"><p>"Istalol". Drugs.com. 1 August 2018. 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