| Propranolol Action Pathway |  | Drug Action | ATP / Propranolol / Potassium cation / Calcium |
| Propranolol B1-Adrenergic Cardiac Muscle Relaxation Action Pathway |  | Drug Action | ATP / Propranolol / Calcium |
| Propranolol B2-Adrenergic Vasoconstriction Action Pathway |  | Drug Action | ATP / Propranolol / Potassium cation / Calcium / Magnesium cation / Cyclic adenosine monophosphate |
| Propyl alcohol Drug Metabolism |  | Metabolic | Propyl alcohol |
| Propylene glycol Drug Metabolism |  | Metabolic | Propylene glycol |
| Propylhexedrine Drug Metabolism |  | Metabolic | Propylhexedrine |
| Propylthiouracil Drug Metabolism |  | Metabolic | Propylthiouracil |
| Prostaglandin |  | Physiological | Glutathione / Dinoprostone / Calcium / Mesoheme / Prostaglandin G2 / Arachidonic Acid |
| Protein C Action Pathway |  | Drug Action | Calcium / Protein C |
| Proxibarbal Drug Metabolism |  | Metabolic | Proxibarbal |
| Prucalopride Action Pathway |  | Drug Action | ATP / Potassium cation / Calcium / Magnesium cation / Cyclic adenosine monophosphate / Pyrophosphoric acid / Prucalopride |
| Prussian blue Drug Metabolism |  | Metabolic | Prussian blue |
| Pseudoephedrine Action Pathway |  | Drug Action | Ascorbic acid / Norepinephrine / Pseudoephedrine / Dopamine / Calcium / Magnesium cation / Pyrroloquinoline Quinone |
| Pseudoephedrine Metabolism |  | Metabolic | Pseudoephedrine / Mesoheme |
| Pterine Biosynthesis |  | Metabolic | NADH / Sapropterin / Zinc / Formic acid / D-threo-neopterin / Triphosphoric acid |
| Purine Metabolism |  | Metabolic | Tetrahydrofolic acid / Aspartic acid / L-Glutamine / Adenosine phosphate / Glutamic acid / Glycine / NADH / ATP / Adenine / Adenosine / Potassium cation / Calcium / Magnesium cation / Zinc / 5-O-phosphono-alpha-D-ribofuranosyl diphosphate / Uric acid / AICA ribonucleotide / Guanosine-5'-Monophosphate / Xanthine / Guanine / Cyclic adenosine monophosphate / Mesoheme / Guanosine / Ribose-1-Phosphate / Flavin adenine dinucleotide / Hypoxanthine / Pyrophosphoric acid / Maleic acid / Inosine / 2'-Deoxyguanosine-5'-Monophosphate |
| Purine Nucleoside Phosphorylase Deficiency |  | Disease | Tetrahydrofolic acid / Aspartic acid / L-Glutamine / Adenosine phosphate / Glutamic acid / Glycine / NADH / ATP / Adenine / Adenosine / Potassium cation / Calcium / Magnesium cation / Zinc / 5-O-phosphono-alpha-D-ribofuranosyl diphosphate / Uric acid / AICA ribonucleotide / Guanosine-5'-Monophosphate / Xanthine / Guanine / Cyclic adenosine monophosphate / Mesoheme / Guanosine / Ribose-1-Phosphate / Flavin adenine dinucleotide / Hypoxanthine / Pyrophosphoric acid / Maleic acid / Inosine / 2'-Deoxyguanosine-5'-Monophosphate |
| Purine Nucleoside Phosphorylase Deficiency |  | Disease | Tetrahydrofolic acid / Aspartic acid / L-Glutamine / Adenosine phosphate / Glutamic acid / Glycine / NADH / ATP / Adenine / Adenosine / Potassium cation / Calcium / Magnesium cation / Zinc / 5-O-phosphono-alpha-D-ribofuranosyl diphosphate / Uric acid / AICA ribonucleotide / Guanosine-5'-Monophosphate / Xanthine / Guanine / Cyclic adenosine monophosphate / Mesoheme / Guanosine / Ribose-1-Phosphate / Flavin adenine dinucleotide / Hypoxanthine / Pyrophosphoric acid / Maleic acid / Inosine / 2'-Deoxyguanosine-5'-Monophosphate |
| Pyrantel Drug Metabolism |  | Metabolic | Pyrantel |
| Pyrazinamide Action Pathway |  | Drug Action | Pyrazinamide / Sapropterin / Mesoheme / Flavin adenine dinucleotide / Flavin mononucleotide |
| Pyridostigmine Action Pathway |  | Drug Action | Choline / Pyridostigmine / Calcium / Magnesium cation / Acetylcholine / Acetic acid |
| Pyridoxine Dependency with Seizures |  | Disease | Pyridoxal phosphate / Lysine / Glutamic acid / NADH / Oxogluric acid / Flavin adenine dinucleotide / L-Saccharopine |
| Pyridoxine Dependency with Seizures |  | Disease | Pyridoxal phosphate / Lysine / Glutamic acid / NADH / Oxogluric acid / Flavin adenine dinucleotide / L-Saccharopine |
| Pyrimidine Metabolism |  | Metabolic | L-Glutamine / ATP / Calcium / Magnesium cation / Iron / Zinc / 5-O-phosphono-alpha-D-ribofuranosyl diphosphate / Thymidine monophosphate / Dihydrouracil / Dihydroorotic Acid / Orotic acid / Cytidine-5'-Triphosphate / Uridine / Orotidylic acid / Ribose-1-Phosphate / beta-Alanine / Flavin adenine dinucleotide / Flavin mononucleotide / Uracil / Uridine-5'-Diphosphate / Thymine / Uridine monophosphate / Deoxyuridine monophosphate / Pyrophosphoric acid / N-Carbamoylaspartic acid / Thymidine |
| Pyrrobutamine H1-Antihistamine Action |  | Drug Action | Calcium |