Amritarishtam is also known as Amrutarishta,amritarista.
Its usage:
It is one of the widely used medicine in the treatment of fever, and improves immunity. Also in case of rheumatic fevers.
Safe in lower doses, for kids above 3 years of age.
Over-dosage should be strictly avoided.
Pregnancy and lactation:
Best to avoid during pregnancy, however can be taken after consulting.
Dosage:
12 – 24 ml. one or two times a day, usually advised after food.
If needed, equal quantity of water can be added before consumption.
Amrutarishta ingredients:
Amrita (Giloya – Indian tinospora) – Stem – 4.8 kg
Bilva (Bae l- Aegle marmelos) – Stem bark / root – 480 g
Shyonaka (Oroxylum indicum) – Stem bark / root  – 480 g
Gambhari (Gmelina arborea) – Stem bark / root  – 480 g
Patala (Stereospermum suaveolens) – Stem bark / root  – 480 g
Agnimantha (Premna mucronata) – Stem bark / root  – 480 g
Shalaparni (Desmodium gangeticum) – Root / whole plant – 480 g
Prishnaparni  (Uraria picta) – – Root / whole plant – 480 g
Brihati (Solanum melongena var. Indicum) – – Root / whole plant – 480 g
Kantakari (Solanum surattense) –  Root / whole plant – 480 g
Gokshura – Tribulus terrestris -Root / whole plant – 480 g
water for decoction – 49.152 liters
Boiled and reduced to 12.288 liters
Guda – Jaggery – 14.4 kg
Prakshepa Dravya
Ajaji – Shweta Jiraka – Cuminum cyminum – Fruit – 768 g
Raktapushpaka – Parpataka (Fumaria parviflora) – whole plant – 96 g
Saptacchada (Saptaparna) – Alstonia scholaris – Stem bark – 48 g
Shunti – Ginger – rhizome – 48 g
Maricha – Black pepper -Fruit – 48 g
Pippali – Long pepper fruit – 48 g
Nagakeshara (Mesua ferrea) – Stamen – 48 g
Abda – Musta (Cyperus rotundus) – 48 g
Katuki (Picrorrhriza kurroa) – Rhizome – 48 g
Prativisha – Ativisha  (Aconitum heterophyllum) -Root – 48 g
Vatsabeeja – Indrayava (Holarrhena antidysenterica) – Seed – 48 g
Reference 
Bhaishaj Ratnavali Jvaradhikara .