Methylphenobarbital may increase the hypotensive activities of Timolol. Timolol may increase the hypotensive activities of Temocapril. Timolol may increase the hypoglycemic activities of Glyburide. The serum concentration of Lidocaine can be increased when it is combined with Timolol. 1,10-Phenanthroline may increase the bradycardic activities of Timolol. Timolol may decrease the bronchodilatory activities of Phenylpropanolamine. Pirlindole may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Candesartan cilexetil. Timolol may increase the bradycardic activities of Beractant. The risk or severity of adverse effects can be increased when Olmesartan is combined with Timolol. Timolol may increase the hypoglycemic activities of Insulin Pork. The risk or severity of adverse effects can be increased when Carbetocin is combined with Timolol. The metabolism of Timolol can be decreased when combined with Terbinafine. Bufexamac may decrease the antihypertensive activities of Timolol. Barbital may increase the hypotensive activities of Timolol. Hexobarbital may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Arecoline. The risk or severity of adverse effects can be increased when Nitrendipine is combined with Timolol. Indomethacin may decrease the antihypertensive activities of Timolol. Tarenflurbil may decrease the antihypertensive activities of Timolol. Timolol may increase the hypoglycemic activities of Acetohexamide. The metabolism of Timolol can be decreased when combined with Celecoxib. The risk or severity of adverse effects can be increased when Timolol is combined with Levobunolol. Dihydroergotamine may increase the atrioventricular blocking (AV block) activities of Timolol. Mebanazine may increase the hypotensive activities of Timolol. Lofexidine may increase the atrioventricular blocking (AV block) activities of Timolol. Norepinephrine may increase the atrioventricular blocking (AV block) activities of Timolol. Paliperidone may increase the atrioventricular blocking (AV block) activities of Timolol. Timolol may decrease the bronchodilatory activities of Salbutamol. Amiodarone may increase the bradycardic activities of Timolol. Ketanserin may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Bendroflumethiazide. Neostigmine may increase the bradycardic activities of Timolol. The risk or severity of adverse effects can be increased when Bepridil is combined with Timolol. Bosentan may increase the hypotensive activities of Timolol. Timolol may increase the orthostatic hypotensive activities of Duloxetine. Disopyramide may increase the bradycardic activities of Timolol. The risk or severity of adverse effects can be increased when Sevoflurane is combined with Timolol. The serum concentration of Timolol can be decreased when it is combined with Rifaximin. The risk or severity of adverse effects can be increased when Timolol is combined with Amlodipine. The risk or severity of adverse effects can be increased when Nabilone is combined with Timolol. The serum concentration of Timolol can be decreased when it is combined with Lumacaftor. Timolol may increase the hypotensive activities of Bupranolol. The metabolism of Timolol can be increased when combined with Fosphenytoin. PTC299 may decrease the antihypertensive activities of Timolol. Timolol may increase the hypotensive activities of Ambrisentan. Safrazine may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Metolazone. Brimonidine may increase the antihypertensive activities of Timolol. Mefenamic acid may decrease the antihypertensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Losartan. The serum concentration of Timolol can be increased when it is combined with Vemurafenib. Bretylium may increase the bradycardic activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Sotalol. Timolol may increase the hypotensive activities of Deserpidine. Diclofenac may decrease the antihypertensive activities of Timolol. Amobarbital may increase the hypotensive activities of Timolol. The serum concentration of Timolol can be increased when it is combined with Levomilnacipran. Timolol may increase the bradycardic activities of Deslanoside. Alimemazine may increase the hypotensive activities of Timolol. The serum concentration of Timolol can be increased when it is combined with Propafenone. Malathion may increase the bradycardic activities of Timolol. Bromfenac may decrease the antihypertensive activities of Timolol. Demecarium may increase the bradycardic activities of Timolol. The metabolism of Timolol can be increased when combined with Phenytoin. Timolol may increase the hypotensive activities of Vincamine. Choline magnesium trisalicylate may decrease the antihypertensive activities of Timolol. The metabolism of Timolol can be decreased when combined with Sertraline. Timolol may decrease the bronchodilatory activities of Terbutaline. Parthenolide may decrease the antihypertensive activities of Timolol. Alclofenac may decrease the antihypertensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Bethanechol. Travoprost may increase the hypotensive activities of Timolol. Mefloquine may increase the bradycardic activities of Timolol. Timolol may increase the hypotensive activities of Hexamethonium. Timolol may decrease the bronchodilatory activities of Fenoterol. The risk or severity of adverse effects can be increased when Timolol is combined with GTS-21. Timolol may increase the hypoglycemic activities of Glimepiride. The risk or severity of adverse effects can be increased when Amphotericin B is combined with Timolol. Suprofen may decrease the antihypertensive activities of Timolol. The risk or severity of adverse effects can be increased when Conivaptan is combined with Timolol. Timolol may increase the hypotensive activities of Polythiazide. Carprofen may decrease the antihypertensive activities of Timolol. Quinine may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Isosorbide Mononitrate. Timolol may increase the hypotensive activities of Terlipressin. The serum concentration of Timolol can be decreased when it is combined with Rifapentine. The risk or severity of adverse effects can be increased when Arsenic trioxide is combined with Timolol. Carbaspirin calcium may decrease the antihypertensive activities of Timolol. Piroxicam may decrease the antihypertensive activities of Timolol. Timolol may decrease the bronchodilatory activities of Salmeterol. The metabolism of Timolol can be decreased when combined with Etravirine. Physostigmine may increase the bradycardic activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Enalapril. The risk or severity of adverse effects can be increased when Timolol is combined with Canagliflozin. Timolol may increase the hypoglycemic activities of Tolbutamide. Timolol may decrease the bronchodilatory activities of Bambuterol. The risk or severity of adverse effects can be increased when Timolol is combined with Nimodipine. The metabolism of Timolol can be decreased when combined with Nevirapine. The metabolism of Timolol can be decreased when combined with Chloroquine. Seratrodast may decrease the antihypertensive activities of Timolol. The risk or severity of adverse effects can be increased when Pramipexole is combined with Timolol. The risk or severity of adverse effects can be increased when Esmolol is combined with Timolol. Timolol may increase the orthostatic hypotensive activities of Trimazosin. The metabolism of Timolol can be decreased when combined with Ticlopidine. The risk or severity of adverse effects can be increased when Timolol is combined with Varenicline. Timolol may increase the hypotensive activities of Dorzolamide. Procarbazine may increase the hypotensive activities of Timolol. Phenobarbital may increase the hypotensive activities of Timolol. Sulindac may decrease the antihypertensive activities of Timolol. Timolol may increase the hypotensive activities of Phenoxybenzamine. Timolol may increase the hypotensive activities of Guanethidine. Isoxicam may decrease the antihypertensive activities of Timolol. Molsidomine may increase the hypotensive activities of Timolol. Icatibant may decrease the antihypertensive activities of Timolol. The metabolism of Timolol can be decreased when combined with Topiramate. Bethanidine may increase the atrioventricular blocking (AV block) activities of Timolol. Diazoxide may increase the hypotensive activities of Timolol. The risk or severity of adverse effects can be increased when Paclitaxel is combined with Timolol. Alfentanil may increase the bradycardic activities of Timolol. Antipyrine may decrease the antihypertensive activities of Timolol. Ambenonium may increase the bradycardic activities of Timolol. The risk or severity of adverse effects can be increased when Timolol is combined with Nesiritide. Timolol may increase the hypotensive activities of Candesartan. The risk or severity of adverse effects can be increased when Timolol is combined with Metipranolol. Timolol may increase the hypotensive activities of Macitentan. The risk or severity of adverse effects can be increased when Timolol is combined with Fosinopril. The risk or severity of adverse effects can be increased when Timolol is combined with Methazolamide. The risk or severity of adverse effects can be increased when Timolol is combined with Azilsartan medoxomil. The risk or severity of adverse effects can be increased when Chlorpromazine is combined with Timolol.