participants are excluded from the study if any of the following criteria apply: * pregnant or breastfeeding * history of hiv * ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs \[nsaids\]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta 1. drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; 2. tizanidine (cyp1a2) substrate; 3. drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors \[ssris\]/serotonin norepinephrine reuptake inhibitors \[snris\]); 4. angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; 5. diuretics; 6. digoxin * ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial * history of immunosuppression * history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids * rejection of participation at the discretion of the principal investigator or sponsor * any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (\<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium \<3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) \>5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.

participants are excluded from the study if any of the following criteria apply: * pregnant or breastfeeding * history of hiv * ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs \[nsaids\]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta 1. drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; 2. tizanidine (cyp1a2) substrate; 3. drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors \[ssris\]/serotonin norepinephrine reuptake inhibitors \[snris\]); 4. angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; 5. diuretics; 6. digoxin * ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial * history of immunosuppression * history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids * rejection of participation at the discretion of the principal investigator or sponsor * any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (\<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium \<3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) \>5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.

participants are excluded from the study if any of the following criteria apply: pregnant or breastfeeding history of hiv ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs [nsaids]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; tizanidine (cyp1a2) substrate; drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors [ssris]/serotonin norepinephrine reuptake inhibitors [snris]); angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; diuretics; digoxin ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial history of immunosuppression history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids rejection of participation at the discretion of the principal investigator or sponsor any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium <3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) >5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.

participants are excluded from the study if any of the following criteria apply: pregnant or breastfeeding history of hiv ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs [nsaids]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; tizanidine (cyp1a2) substrate; drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors [ssris]/serotonin norepinephrine reuptake inhibitors [snris]); angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; diuretics; digoxin ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial history of immunosuppression history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids rejection of participation at the discretion of the principal investigator or sponsor any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium <3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) >5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.

participants are excluded from the study if any of the following criteria apply: - pregnant or breastfeeding - history of hiv - ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs [nsaids]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta 1. drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; 2. tizanidine (cyp1a2) substrate; 3. drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors [ssris]/serotonin norepinephrine reuptake inhibitors [snris]); 4. angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; 5. diuretics; 6. digoxin - ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial - history of immunosuppression - history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids - rejection of participation at the discretion of the principal investigator or sponsor - any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium <3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) >5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.

participants are excluded from the study if any of the following criteria apply: - pregnant or breastfeeding - history of hiv - ongoing treatment that cannot be temporarily discontinued during the study: anti-inflammatory treatment (nonsteroidal anti-inflammatory drugs [nsaids]);corticosteroids; antimalarials; antiarrhythmics; tricyclic antidepressants; natalizumab; quinolones; macrolides; and agalsidase alfa and beta 1. drugs dependent on gastric ph for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; 2. tizanidine (cyp1a2) substrate; 3. drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors [ssris]/serotonin norepinephrine reuptake inhibitors [snris]); 4. angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers (arb), or beta-blockers; 5. diuretics; 6. digoxin - ongoing famotidine, celecoxib, or other covid-19 clinical investigational treatment(s) within the past 30 days or current participation in another investigational clinical trial - history of immunosuppression - history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nsaids - rejection of participation at the discretion of the principal investigator or sponsor - any contraindication for famotidine or celecoxib treatment: a. famotidine or celecoxib hypersensitivity; b. retinopathy, visual field or visual acuity disturbances; c. history of cardiovascular disease, such as congestive heart failure, qt prolongation, bradycardia (<50 bpm), ventricular tachycardia, other arrhythmias, as determined at screening electrocardiogram (ecg) or medical history; d. potassium <3 meq/l (milliequivalent/liter) as determined at visit 1; e. aspartate aminotransferase (ast) or alanine aminotransferase (alt) >5 upper normal limit, as determined at visit 1; f. previous myocardial infarction; e. myasthenia gravis; h. psoriasis or porphyria; i. glomerular clearance, 60 ml/min; j. previous history of severe hypoglycemia; k. known or suspected to be poor cyp2c9 metabolizers based on genotype or previous history or experience with other cyp2c9 substrates, such as warfarin and phenytoin; l. moderate or severe hepatic impairment, e.g., child-pugh class b or c.